# How do you simplify (3x-7)^3?

May 23, 2017

$27 {x}^{3} - 189 {x}^{2} + 441 x - 343$

#### Explanation:

I'm not sure you can simplify this expression. It seems to be in simplest form. However, if the question had been to expand this expression then here are the steps:

$\left(3 x - 7\right) \left(3 x - 7\right) \left(3 x - 7\right)$

Expand the first two terms using FOIL

$\left(9 {x}^{2} - 42 x + 49\right) \left(3 x - 7\right)$

Multiply the $\left(3 x - 7\right)$ term through

$9 {x}^{2} \left(3 x - 7\right) - 42 x \left(3 x - 7\right) + 49 \left(3 x - 7\right)$

Simplify

$27 {x}^{3} - 63 {x}^{2} - 126 {x}^{2} + 294 x + 147 x - 343$

Combine like terms

$27 {x}^{3} - 189 {x}^{2} + 441 x - 343$