Asked by Dan

Solve the system of equations algebraically. Show all of your steps.
y=x^2+2x
y=3x+20
Answered by scott
3x + 20 = x^2 + 2x ... 0 = x^2 - x - 20 ... 0 = (x - 5)(x + 4) ... x = 5 , x = -4
Answered by Henry.
Y = x^2 + 2x.
Y = 3x + 20.
In Eq1, replace Y with 3x + 20:
3x + 20 = x^2 + 2x,
x^2 + 2x - 3x -20 = 0,
x^2 - x - 20 = 0.
Solve the Eq by factoring.