Simplify:

left bracket, minus, 9, x, right bracket, left bracket, minus, 2, x, cubed, right bracket
(−9x)(−2x
3
)

To simplify the expression, you can distribute the negative signs across the terms:

(−9x)(−2x³)

This will give you:

(−9x) × (−2) × (x³)

Using the properties of multiplication, you can multiply the coefficients and add the exponents of x:

= 18x^(1+3)

= 18x^4