This is the demo showing how match quadratic equations in the graphs. Plug in x=0. So everything with x cannot disappear. There is only one negative three in the equations. Let's look at the equations that has the four as y in the set. One of the difference between each equations are the negative in front of the x square and not in the second one. B is the set which opens down and C is the set which opens. Now lets look zero as y on each set. Both of them are opened. Let's look at X intercepts.