Question

Look at the equations in this system. Where do the lines intersect?

Explain how you can tell without graphing or solving the system.

y = 7x + 4
y = -5x +4

Answer 1

(0,4)

Since the lines intersect you know the y’s will be the same, so you can make the two equations into one 7x +4 = -5x +4 then you just have to simplify and get 12x = 0, then x= 0. Next you have to find the y by plugging in the x so 7(0) +4 which is 4 so the final answer is (0,4)