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

Rewrite the expression as $\left(3 x + 7\right) \left(3 x + 7\right) \left(3 x + 7\right)$ and expand.
$\left(3 x + 7\right) \left(3 x + 7\right) \left(3 x + 7\right)$
$\left(9 {x}^{2} + 21 x + 21 x + 49\right) \left(3 x + 7\right)$
$\left(9 {x}^{2} + 42 x + 49\right) \cdot \left(3 x + 7\right) = \left(343 + 441 x + 189 {x}^{2} + 27 {x}^{3}\right)$