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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?

Respuesta :

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)