SOLUTION: (7x^2-x-4)-(9x^2-10x+8)+(12x^2+4x-6)

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Question 131928:
(7x^2-x-4)-(9x^2-10x+8)+(12x^2+4x-6)
Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
7X^2-X-4
-9X^2+10X-8
12X^2+4X-6
----------------------------
10X^2+13X-18
USING THE QUADRATIC EQUATION:x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ WE GET:
X=(-13+-SQR[13^2-4*10*-18])/2*10
X=(-13+-SQRT[169+720])/20
X=(-13+-SQRT889]/20
X=(-13+-29.82)/20
X=(-13+29.82)/20
X=16.82/20
X=.84 ANSWER.
X=(-13-29.82)/20
X=-42.82/20
X=-2.14 ANSWER.