Solve =(3x^{2}+1)^2*(x-x^2)[18x(x-x^2)+2(3x^2+1)(1-x)]

$$= ( 3 x ^ { 2 } + 1 ) ^ { 2 } \cdot ( x - x ^ { 2 } ) [ 18 x ( x - x ^ { 2 } ) + 2 ( 3 x ^ { 2 } + 1 ) ( 1 - x ) ]$$

Evaluate

$$2x\left(12x^{2}+1\right)\left(\left(1-x\right)\left(3x^{2}+1\right)\right)^{2}$$

Solution Steps

Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(3x^{2}+1\right)^{2}.

$$\left(9\left(x^{2}\right)^{2}+6x^{2}+1\right)\left(x-x^{2}\right)\left(18x\left(x-x^{2}\right)+2\left(3x^{2}+1\right)\left(1-x\right)\right)$$

To raise a power to another power, multiply the exponents. Multiply 2 and 2 to get 4.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(18x\left(x-x^{2}\right)+2\left(3x^{2}+1\right)\left(1-x\right)\right)$$

Use the distributive property to multiply 18x by x-x^{2}.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(18x^{2}-18x^{3}+2\left(3x^{2}+1\right)\left(1-x\right)\right)$$

Use the distributive property to multiply 2 by 3x^{2}+1.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(18x^{2}-18x^{3}+\left(6x^{2}+2\right)\left(1-x\right)\right)$$

Use the distributive property to multiply 6x^{2}+2 by 1-x.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(18x^{2}-18x^{3}+6x^{2}-6x^{3}+2-2x\right)$$

Combine 18x^{2} and 6x^{2} to get 24x^{2}.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(24x^{2}-18x^{3}-6x^{3}+2-2x\right)$$

Combine -18x^{3} and -6x^{3} to get -24x^{3}.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(24x^{2}-24x^{3}+2-2x\right)$$

Use the distributive property to multiply 9x^{4}+6x^{2}+1 by x-x^{2}.

$$\left(9x^{5}-9x^{6}+6x^{3}-6x^{4}+x-x^{2}\right)\left(24x^{2}-24x^{3}+2-2x\right)$$

Use the distributive property to multiply 9x^{5}-9x^{6}+6x^{3}-6x^{4}+x-x^{2} by 24x^{2}-24x^{3}+2-2x and combine like terms.

$$378x^{7}-432x^{8}+198x^{5}-324x^{6}+216x^{9}+38x^{3}-72x^{4}+2x-4x^{2}$$

Expand

$$216x^{9}-432x^{8}+378x^{7}-324x^{6}+198x^{5}-72x^{4}+38x^{3}-4x^{2}+2x$$

Solution Steps

Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(3x^{2}+1\right)^{2}.

$$\left(9\left(x^{2}\right)^{2}+6x^{2}+1\right)\left(x-x^{2}\right)\left(18x\left(x-x^{2}\right)+2\left(3x^{2}+1\right)\left(1-x\right)\right)$$

To raise a power to another power, multiply the exponents. Multiply 2 and 2 to get 4.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(18x\left(x-x^{2}\right)+2\left(3x^{2}+1\right)\left(1-x\right)\right)$$

Use the distributive property to multiply 18x by x-x^{2}.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(18x^{2}-18x^{3}+2\left(3x^{2}+1\right)\left(1-x\right)\right)$$

Use the distributive property to multiply 2 by 3x^{2}+1.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(18x^{2}-18x^{3}+\left(6x^{2}+2\right)\left(1-x\right)\right)$$

Use the distributive property to multiply 6x^{2}+2 by 1-x.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(18x^{2}-18x^{3}+6x^{2}-6x^{3}+2-2x\right)$$

Combine 18x^{2} and 6x^{2} to get 24x^{2}.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(24x^{2}-18x^{3}-6x^{3}+2-2x\right)$$

Combine -18x^{3} and -6x^{3} to get -24x^{3}.

$$\left(9x^{4}+6x^{2}+1\right)\left(x-x^{2}\right)\left(24x^{2}-24x^{3}+2-2x\right)$$

Use the distributive property to multiply 9x^{4}+6x^{2}+1 by x-x^{2}.

$$\left(9x^{5}-9x^{6}+6x^{3}-6x^{4}+x-x^{2}\right)\left(24x^{2}-24x^{3}+2-2x\right)$$

Use the distributive property to multiply 9x^{5}-9x^{6}+6x^{3}-6x^{4}+x-x^{2} by 24x^{2}-24x^{3}+2-2x and combine like terms.

$$378x^{7}-432x^{8}+198x^{5}-324x^{6}+216x^{9}+38x^{3}-72x^{4}+2x-4x^{2}$$