Solve for x
x=-2
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x^{3}+6x^{2}+12x+8-\left(x-2\right)^{3}=12x\left(x-1\right)-8
Use binomial theorem \left(a+b\right)^{3}=a^{3}+3a^{2}b+3ab^{2}+b^{3} to expand \left(x+2\right)^{3}.
x^{3}+6x^{2}+12x+8-\left(x^{3}-6x^{2}+12x-8\right)=12x\left(x-1\right)-8
Use binomial theorem \left(a-b\right)^{3}=a^{3}-3a^{2}b+3ab^{2}-b^{3} to expand \left(x-2\right)^{3}.
x^{3}+6x^{2}+12x+8-x^{3}+6x^{2}-12x+8=12x\left(x-1\right)-8
To find the opposite of x^{3}-6x^{2}+12x-8, find the opposite of each term.
6x^{2}+12x+8+6x^{2}-12x+8=12x\left(x-1\right)-8
Combine x^{3} and -x^{3} to get 0.
12x^{2}+12x+8-12x+8=12x\left(x-1\right)-8
Combine 6x^{2} and 6x^{2} to get 12x^{2}.
12x^{2}+8+8=12x\left(x-1\right)-8
Combine 12x and -12x to get 0.
12x^{2}+16=12x\left(x-1\right)-8
Add 8 and 8 to get 16.
12x^{2}+16=12x^{2}-12x-8
Use the distributive property to multiply 12x by x-1.
12x^{2}+16-12x^{2}=-12x-8
Subtract 12x^{2} from both sides.
16=-12x-8
Combine 12x^{2} and -12x^{2} to get 0.
-12x-8=16
Swap sides so that all variable terms are on the left hand side.
-12x=16+8
Add 8 to both sides.
-12x=24
Add 16 and 8 to get 24.
x=\frac{24}{-12}
Divide both sides by -12.
x=-2
Divide 24 by -12 to get -2.
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