How To: Use applications of rational expressions in algebra

I need help with my home work, is 1 am and still dont get it, please please help me with Simplifying rational expressions?

1) 5/2x
3) x/x-8

5) 3/15x-20

Problem 7.2,
3) 1+2/9

9) x^2+9x+14/x+7*x/x+2

37) 15/x/3/2x

Problem 7.3,
1) 7x/13+2x/13

3) 8x/15+x/15

55) 3-x/x-7-2x-5/7-x

Problem 7.4
1) 7/15x^2+13/24x

3) 8/15x^2+5/6x^5


5) 4/x-3+7/x+1




Problem 7.5, (1; 5; 14)
1) 1/2+1/4/1/2+1/3

5) 2/5-1/3/2/3-3/4

14) 1/y-3/4/1/y+2/3

Problem 7.6, (1; 7; 8)

1)x/3=x/2-2

7) 2/x+1/3=4/x

8) 5/x+1/3=6/x


Problem 7.7, (37; 40; 49)

37) What is proportion? Give an example with your description.

40) What are corresponding angels in similar triangle?

49) Ben can prepare a company report in 42 hours. How long will take them working together to prepare four company reports?

Problem 7.8 (1; 3; 17)
1) y varies directly as x. y=65 when x=5 find y when x = 12.

3. y varies inversely as x. y=12 when x=5, find y when x=2.

17. A varies jointly as z and the sum of y and x.