Solve the system equations

Question

y=4x+8,x^2+7x-20

I'm truly lost

Answer 1

I assume your two equations are

y = 4x+8
y = x^2+7x-20

So, just set them equal:

x^2+7x-20 = 4x+8
x^2+3x-28 = 0
(x+7)(x-4) = 0

x = -7 or 4

See

http://www.wolframalpha.com/input/?i=x%5E2%2B7x-20+%3D+4x%2B8