Solve -xleft(x-7.2right)left(x-15.+6right)

$$-x \left( x-7.2 \right) \left( x-15.+6 \right)$$

Evaluate

$$-x\left(x-9\right)\left(x-7.2\right)$$

Solution Steps

Add -15 and 6 to get -9.

$$\left(-x\right)\left(x-7.2\right)\left(x-9\right)$$

Use the distributive property to multiply -x by x-7.2.

$$\left(\left(-x\right)x-7.2\left(-x\right)\right)\left(x-9\right)$$

Multiply -7.2 and -1 to get 7.2.

$$\left(\left(-x\right)x+7.2x\right)\left(x-9\right)$$

Apply the distributive property by multiplying each term of \left(-x\right)x+7.2x by each term of x-9.

$$\left(-x\right)x^{2}-9\left(-x\right)x+7.2x^{2}-64.8x$$

Multiply -9 and -1 to get 9.

$$\left(-x\right)x^{2}+9xx+7.2x^{2}-64.8x$$

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

$$\left(-x\right)x^{2}+9x^{2}+7.2x^{2}-64.8x$$

Combine 9x^{2} and 7.2x^{2} to get 16.2x^{2}.

$$\left(-x\right)x^{2}+16.2x^{2}-64.8x$$

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

$$-x^{3}+16.2x^{2}-64.8x$$

Expand

$$-\left(x^{3}-\frac{81x^{2}}{5}+\frac{324x}{5}\right)$$

Solution Steps

Add -15 and 6 to get -9.

$$\left(-x\right)\left(x-7.2\right)\left(x-9\right)$$

Use the distributive property to multiply -x by x-7.2.

$$\left(\left(-x\right)x-7.2\left(-x\right)\right)\left(x-9\right)$$

Multiply -7.2 and -1 to get 7.2.

$$\left(\left(-x\right)x+7.2x\right)\left(x-9\right)$$

Apply the distributive property by multiplying each term of \left(-x\right)x+7.2x by each term of x-9.

$$\left(-x\right)x^{2}-9\left(-x\right)x+7.2x^{2}-64.8x$$

Multiply -9 and -1 to get 9.

$$\left(-x\right)x^{2}+9xx+7.2x^{2}-64.8x$$

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

$$\left(-x\right)x^{2}+9x^{2}+7.2x^{2}-64.8x$$

Combine 9x^{2} and 7.2x^{2} to get 16.2x^{2}.

$$\left(-x\right)x^{2}+16.2x^{2}-64.8x$$

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

$$-x^{3}+16.2x^{2}-64.8x$$