SOLUTION: -3x^3+54x=21x^2

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Question 582843: -3x^3+54x=21x^2
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
-3x%5E3%2B54x=21x%5E2
-3x%5E3-21x%5E2%2B54x=0
-3x(x^2+7x-18)=0

-3x(x^2+9x-2x-18)=0
(-3x)(x(x+9)-2(x+9))=0


-3x(x+9)(x-2))=0
Either
-3x= 0 , x=0
OR
X+=0 x=-9
OR
x-2=0
x=2
x= 0, 2,-9