Question

Solve the system of equations algebraically show all of your steps

y=x^2+2x
y=3x+20

is it x=2.8 and y=28.5?

Answer 1

If y = x^2 + 2x and y = 3x + 20

Then

x^2 + 2x = 3x + 20

x^2 - x - 20 = 0

(x - 5)(x + 4) = 0

x = 5, - 4

For x = 5, y = 3(5) + 20 = 35

For x = - 4, y = 3(-4) + 20 = 8

(5, 35), (-4, 8)