Solve 3x(-x^2+4x-7)

$$3 x ( - x ^ { 2 } + 4 x - 7 )$$

Expand

$$-3x^{3}+12x^{2}-21x$$

Solution Steps

Use the distributive property to multiply 3x by -x^{2}+4x-7.

$$3x\left(-x^{2}\right)+12x^{2}-21x$$

Multiply 3 and -1 to get -3.

$$-3xx^{2}+12x^{2}-21x$$

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

$$-3x^{3}+12x^{2}-21x$$

Evaluate

$$3x\left(-x^{2}+4x-7\right)$$

Solution Steps

Use the distributive property to multiply 3x by -x^{2}+4x-7.

$$3x\left(-x^{2}\right)+12x^{2}-21x$$

Multiply 3 and -1 to get -3.

$$-3xx^{2}+12x^{2}-21x$$

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

$$-3x^{3}+12x^{2}-21x$$