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How To: Solve simple algebraic equations

This is a great series of videos showing you how to solve simple algebraic equations. The first video demonstrates solving equations using addition or subtraction, the second deals with solving equations using multiplication or division, and the third shows how to solve multistep equations.

How To: Factor trinomials with 2 variables & GCF by grouping

In the video, the process of factoring trinomials is described. A trinomial that cannot be easily factored in its original form is shown. It is simplified by pulling out the greatest common factor. After that, a trinomial that is easier to factor is shown. Next, the simplified trinomial is broken up into four terms so that factoring by grouping can be done. Once again, a common factor from each pair is taken so that two binomials are created. Once the greatest common factor is added back with...

How To: Solve a system of equations through graphing

This video shows the viewer how to solve simultaneous equations using a graph or ‘graphing’ as it is referred to. This is done by first rearranging both equations so that y is the object of both equations. The equations can then be solved via substitution – the video does not cover this. Using graphing the next step is to plot both of the lines onto the graph. This can be done by substituting varying values of x to give the y co-ordinates. The solution to the linear equation should be the poi...

How To: Use number patterns in math

In this video the instructor shows how to identify patterns in numbers, figures, letters. When given a pattern like 1, 2, 4, 7 try to find the change in each of the successive numbers in the pattern. If you observe carefully you will notice that the difference of the second and first number is one. Similarly the difference of the third and second number is two and this pattern keeps repeating. So this pattern is generated by taking 1 and adding 1 to it. To the next number add 2 to get the thi...

How To: Use a TI89 calculator to graph linear equations

This video shows the user how to use a T189 calculator to plot linear equations. The video demonstration is done using an ‘on screen’ representation of the calculator – there are also verbal instructions. The equations are plotted on the same axis by selecting the ‘y=’ function. The corresponding values of y in terms of x are then inputted into the graphical calculator. Once this has been done for every equation you can get the calculator to display the graph. This then allows you to compare ...

How To: Write a logarithm as a sum or difference of logarithms

This video shows the method to write a logarithm as a sum or difference of logarithms. The square root of the term given is taken out as half according to the rule. Then the numerator and denominator is divided into product of factors. This is broken into the difference of numerator and denominator according to the rule. Finally, the product of factors is expressed as the sum of factors. Now we see the domain of the term. As the term is a square root of the term it should be greater than zero...

How To: Graph lines using x and y intercepts

A line is defined by two connecting points on a graph, and intercepts are the points on both the x- and y-axis, where the line intersects. This video tutorial demonstrates how to graph lines using x and y intercepts in a given area. This instructional video also graphs various examples of equations and explains the associated methodology.

How To: Factor polynomials by grouping

A factoring problem that has to be solved by grouping is easy to identify, because you can always identify if there are any similar terms in a polynomial. Now, if you find any variable common in any terms pull them out as the common leaving the rest of the terms. After pulling out the common terms you can group the rest of the polynomial. Be careful while pulling out signs. Pulling out a positive number does not effect the signs of terms in the polynomial, where as pulling out a negative numb...

How To: Figure out a tip without a calculator

To figure out a tip without a calculator, first remove the pennies amount in the bill. For example, if your bill is $23.76 becomes $23.70. To figure out a 10% tip, move the decimal point one place to the left. So, 23.70 becomes 2.370 or $2.37. Bump up that number to $2.30 or $2.40 or $2.50 cents, depending on your preference. Since 20% equals two times 10%, double the figure you computed for 10%. So, $2.30 becomes $4.60, or $2.40 becomes $4.80 or $2.50 becomes $5.00. Using this method, you wo...

How To: Add and subtract radicals

Radicals are square roots which are not integers; the square roots of 2 or 3 are examples of radicals. The presenters show simple ways of how to add and subtract such radicals. They explain that by using the method of factoring, the addition or subtraction is made very easy. If the square root of 8, for instance, is in some addition sum, it can be factored into the square root of 4 times the square root 2. Since we know that the square root of 4 is 2 this can be simplified to be 2 times the s...

How To: Solve 3 equations with 3 variables

You can solve 3 equations having 3 variables. Here are the 3 equation examples: x+2y+z=10. 2x-y+3z=-5. 2x-3y-5z=27. The goal is to reduce to 2 equations having 2 variables. Multiply bottom equation by (-1). Rewrite 2nd and 3rd equation. 2x-y+3z=-5. Add -2x+3y+5z+-27. Equals 2y+8z=-32. Go back to original equations and multiply by (-2). Then you have -2x -4-2z=-20. plus 2x -y +3z. When you add these 2 equations, the answer is -5y +z = -25. You have now reduced the equations from 3 equations do...

How To: Graph a hyperbola

This video is one in a series of videos dealing with conic sections, in mathematics. This particular video deals with hyperbolas. The teacher, Robert Ahdoot, gives an example of a hyperbola, during which he emphasizes some key points. A hyperbola is identified by an equation containing x squared and y squared, with a minus sign between them. If x is larger, the hyperbola will open to the sides, and if y is larger it will open up and down. He creates hyperbolas, demonstrating where to make asy...

How To: Factor trinomials with the "swing method"

This is a very interesting educational video on how to find the factor trinomials using the swing method. Let us take an example and find the factor trinomials for 2xsquare-13x-45. Let us use the swing method. So now we will get 2xsquare -13x-45. You have to find the suitable factors of 90. It is 18 and 5. If you multiply 18 by 5 you will get 90. You will get (x-18over2)(x+5over2). The final answer is (x-9)(2x+5). Now we have found out the factor trinomials of 2xsquare-13x-45. This swing meth...

How To: Use math rotations in pre-Algebra

On yourteachermathhelp teaches you how to use math rotations in pre-algebra. In this example, the shaded object represents the original one, while the empty object is the new, rotated one. Here, the original object has suffered a quarter of a turn, or a 90 degree turn. You can see that the top of the shaded figure or object has been turned to the left. This is in the opposite direction in which the hands of a clock move. This translates to a 90 degree turn in the counter-clockwise direction. ...

How To: Simplify square roots in math

In this video the instructor shows how to simplify radicals. A radical is nothing but another name for a square root. To find the square root of a simple number the first thing that you need to do is factor it. If you need to compute the square root of a number, you first need to find a number which multiplied by itself gives the original number under the root. For example, to find the square root of 9, you need to find a number which multiplied by itself gives 9. Here the answer is 3. When 3...

How To: Solve a linear system with no solution

A method for solving a linear system with no solution is described. The method is described in 4 steps. The first step in the method is designed to solve a linear system that is described consist of “solving by graphing”. Details for “solving by graphing” first consist of finding points to graph using two different equations. The second step in the method consist of placing the points from both equations on the same graph in order to find out if bo...

How To: Solve rational equations easily

This video revolves around solving rational equations in Algebra 2. When you are given a rational equation, you have to find the greatest common factor and multiply all fractions to get that common factor. If a fraction already has that common factor, then no further step is necessary for that one. Next, you have to multiply all fractions by the greatest common factor to get rid of all denominators. Finally, the remaining equation is simple math and you only need to solve the equation for the...

How To: Find a percentage of a number

This video in the Education category will show you how to find a percentage of a number. For example, what is 12% of 56? The simple way to do this is to find 10% of 56; which is 5. 6. Then you find 1% of 56 is .56. Then you add 10% plus 1% plus 1%, that is, 5. 6 plus .56 plus .56; which is 6. 72. And that’s the answer. The other way to do this is to make decimal out of 12; which is .12. Now multiply .12 by 56 and the product is 6. 72. These are the two methods of finding out a percentage of a...

How To: Simplify expressions involving algebraic radicals

In this video tutorial, viewers learn how to simplify expressions involving algebraic ratios. In some ways, simplifying algebraic radicals is easier than numeric radicals. When we are working with square roots, we need to find the highest even power of a variable to act as out perfect square. When working with cube roots, we look for the highest multiple of 3 as an exponent for our perfect square. This video is very descriptive and clearly explains all the functions of the formula. This video...

How To: Understand parabolas

The instructor in this video uses humor to teach people math, which is not a favorite subject for many. The video goes on to teach the students in the video different ways to cut the conic sections into different shapes. The teacher then focuses on parabolas and defines the formulas. The formula is y = x^2. The rest of the video dissects the equation breaking it down into much more meaningful statements so that the average human being who is not very good at math can understand the equation. ...

How To: Add and subtract fractions with different denominators

This video is a simple math video showing how to add and subtract fractions using different denominators. It begins with a man explaining briefly and sitting in front of a piece of paper. He writes out a group of fractions each one with different denominators, ending in three and five. To add appropriately, on must find a common denominator, which is fifteen. So he multiplies each by five and three, raising the denominators to fifteen. This will raise the fractions to six-fifteenths and twent...

How To: Find the area of a circle when you know the diameter

In this video, it is shown how to calculate the area of a circle where the diameter is given. The formula for calculating the area of a circle is pi multiplied by square of radius. Radius is actually half of the diameter. In this video, the diameter is given as 10.6 meters. Hence, the radius will be half of 10.6 which is equal to 5.3 meters. Now, to find the area we shall multiply pi with the square of 5.3. Square of 5.3 is 28.09. If we multiply 28.09 with pi we shall get the area of the circ...

How To: Graph a linear equation

In this video tutorial, viewers learn how to graph a linear equation. The linear equations example used in this video is y= 1/3x-3. The equation to graph a linear equation is y= mx+b. Now substitute each number into the equation. Therefore, m= 1/3 and b= -3. Begin by graphing the Y-intercept. M is the slope and b is the y-intercept. Plot the y-intercept on the -3 axis. Then move up once and to the side 3 times. This video will benefit those viewers who are struggling with this math unit and a...

How To: Graph linear equations with a table of values

The author teaches us how to graph the linear equations with tables. Given a set of linear equations in terms of "x and y", first we have to draw a table having a column each for x and y. We have to enter an arbitrary value of x in that table and substitute that value in the given equation to get the corresponding y value. Once you obtain both x and y values, the next step is to plot them in a graph. Consider an example: in the linear equation x=2y,on substituting an arbitrary value of x=2,we...

How To: Use the laws of logarithms

ProfessorElvisZap teaches you about the laws of logarithms. When x is positive, meaning 0<x. x times y equals y times x. This is the commutative property. x times (y times z) equals (x times y) times z. This is the associative property. x times 1 equals x. This is the multiplicative property. x times x to the power of -1 equals 1. This is the multiplicative inverse property. You can use these properties with addition: a+b=b+a, (a+b)+c=a+(b+c), a+0=a and a+(-a)=0. A logarithm is a homomorphism...

How To: Find a formula describing direct variation

In this video the instructor shows how to find a formula describing direct variation between two variables. Variation between two variables can be either direct variation or indirect variation. If a variable y is in direct variation with a variable x we can write the general equation between them as y = k * x. That is as x varies, y varies directly in relation to x, as a multiple of x. Now if you have the values of y and x, you can substitute them in this general equation which gives you the ...

How To: Use a protractor in geometry

Omar, Hayley, Gary, and Autumn teach us how to use a protractor. They give a bit of information from About.com on the history of protractors. They are used to measure angles. The first protractor was used to help with navigation and invented in 1801. To measure an angle, line up the base of the protractor with 1 line of the angle. The center circle should be on the vertex of the angle. Use the "swivel thing" to find what degree the other end of the angle lines up with. If there isn't one, you...

How To: Solve exponential and logarithmic equations

In this video tutorial the instructor shows how to solve exponential and logarithmic equations. Solving exponential equations can become very difficult if it involves large numbers. To solve these kinds of complex equations you need to get all the numbers to the same base number. The base number raised to some number should give you your original number. Now if you write the numbers as exponents of your base number you can directly equate the exponent part and solve for the missing variable. ...

How To: Find the volume of a sphere with radius r

Are you slightly rusty on your math skills? This video demonstrates how to find the volume of a sphere with a given radius. The first step is to sketch a solid and cross-sectional view of your sphere to get an understanding of the process to come. Next, find a formula for the area of this cross-section. Third, find the limits of integration. This will allow you to take the area of each cross-section in the sphere, not just the singular one you are viewing. Lastly, integrate this formula from ...

How To: Factor trinomials

In this video, the instructor shows how to factor trinomials. An equation is a trinomial if it has three terms. If you factor a trinomial, you are left with two binomials which are the factors of the original trinomial. Multiplying them would result in the original trinomial. Now factor the last numerical term such that the sum or difference of those factors gives you the numerical coefficient of the middle term. Now split the middle term according to the factors obtained in the previous term...

How To: Understand parallel lines & transversals

This video explains the properties of parallel lines and transversals in geometry. The instructor, Robert Ahdoot, uses an analogy in which he compares lines and transversals to the streets of Manhattan, New York. Continuing with this comparison, he goes over corresponding angles of two parallel lines cut by the same transversal, also explaining when they're equal. He then shows where interior and exterior angles may be found, and then goes over whether two angels are same-side or alternate, d...

How To: Graph a linear equation in 3 different ways

In this video tutorial, viewers learn how to graph a linear equation in 3 different ways. The first way is to use the table of values. It is the slowest method but it always work. It is the most useful. The second way is to use the slope-intercept. It is more faster than the table of values and is very versatile. The third way is to use the intercept-intercept. It is the fastest and easiest method to do. This video will benefit those viewers who are learning about graphing in mathematics and ...

How To: Use probability of dependent events

In this video you will learn how to use probability of dependent events. The video starts with a small advertisement to there website http://www.yourteacher.com. Then its followed up by a math instructor taking you through a example problem to help you understand how you can begin solving problems of your own. The problem used in the example is: Andrea has 4 red socks and 8 blue socks in her drawer, she chooses one sock at random and puts it on, she then chooses another sock without looking, ...

How To: Add and subtract integers

In this video the instructor teaches how to add and subtract integers. When adding or subtracting two numbers there can be four kind of situations depending on the signs between the numbers. When you are adding two numbers which are both positive then you move forward on the number line adding the two numbers together to give the result. Similarly when adding two negative numbers together then you move left side of the number line. Go to the left by the value of first number and go further le...

How To: Get the radius and area of a circle with circumference

This video from Your Teacher is one of a range of math solutions. (which is the measurement from the center to the edge when drawn in a straight line) and also the area of the circle, is the amount of total space within its perimeter. The circumference of this circle is 20 pi. The circumference is 2 pi r. So 20 pi is 2 pi r. Which factors down to show that 10 is the radius (10=r). The area is pi r squared. As we know the radius is 10, we can work out the area - 100 pi.

How To: Multiply integers together

In this video the instructor shows how to multiply and divide integers. When multiplying or dividing two numbers if the signs of the two numbers are same then the sign of the result is a positive number. When multiplying or dividing two numbers if the signs of the two numbers are not same then the sign of the result is a negative number. So a positive number multiplied by a positive number gives a positive number. Similarly a negative number multiplied by a negative number gives a positive nu...