SOLUTION: Solve the system of equations by substitution y = x^2 + 2x - 2 and y = 3x + 4

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Question 59830This question is from textbook Alegbra Concepts and Applications
: Solve the system of equations by substitution
y = x^2 + 2x - 2
and
y = 3x + 4
This question is from textbook Alegbra Concepts and Applications

Answer by ankor@dixie-net.com(12692) About Me  (Show Source):
You can put this solution on YOUR website!
y = x^2 + 2x - 2
and
y = 3x + 4;
:
Just substitute (3x+4) for y in the 1st equation:
x^2 + 2x - 2 = y
:
x^2 + 2x - 2 = 3x + 4
:
Perform the necessay math operations to get everything on the left
x^2 + 2x - 3x - 2 - 4 = 0
:
x^2 - 1x - 6 = 0
:
Factor easily to:
(x - 3)(x + 2) = 0
:
x = +3 and x = -2
:
:
Check both solutions by substitution in both equations:
x = +3
3^2 + 2(3) - 2 = 13
and
3(3) + 4 = 13
:
x = -2
(-2)^2 + 2(-2) - 2 = -2
and
3(-2) + 4 = -2