Solve -x(x-4)*(x+4)

$$- x ( x - 4 ) \cdot ( x + 4 )$$

Evaluate

$$x\left(16-x^{2}\right)$$

Solution Steps

Use the distributive property to multiply -x by x-4.

$$\left(\left(-x\right)x-4\left(-x\right)\right)\left(x+4\right)$$

Multiply -4 and -1 to get 4.

$$\left(\left(-x\right)x+4x\right)\left(x+4\right)$$

Apply the distributive property by multiplying each term of \left(-x\right)x+4x by each term of x+4.

$$\left(-x\right)x^{2}+4\left(-x\right)x+4x^{2}+16x$$

To multiply powers of the same base, add their exponents. Add 1 and 2 to get 3.

$$-x^{3}+4\left(-1\right)xx+4x^{2}+16x$$

Multiply x and x to get x^{2}.

$$-x^{3}+4\left(-1\right)x^{2}+4x^{2}+16x$$

Multiply 4 and -1 to get -4.

$$-x^{3}-4x^{2}+4x^{2}+16x$$

Combine -4x^{2} and 4x^{2} to get 0.

$$-x^{3}+16x$$

Expand

$$16x-x^{3}$$

Solution Steps

Use the distributive property to multiply -x by x-4.

$$\left(\left(-x\right)x-4\left(-x\right)\right)\left(x+4\right)$$

Multiply -4 and -1 to get 4.

$$\left(\left(-x\right)x+4x\right)\left(x+4\right)$$

Apply the distributive property by multiplying each term of \left(-x\right)x+4x by each term of x+4.

$$\left(-x\right)x^{2}+4\left(-x\right)x+4x^{2}+16x$$

To multiply powers of the same base, add their exponents. Add 1 and 2 to get 3.

$$-x^{3}+4\left(-1\right)xx+4x^{2}+16x$$

Multiply x and x to get x^{2}.

$$-x^{3}+4\left(-1\right)x^{2}+4x^{2}+16x$$

Multiply 4 and -1 to get -4.

$$-x^{3}-4x^{2}+4x^{2}+16x$$

Combine -4x^{2} and 4x^{2} to get 0.

$$-x^{3}+16x$$