# What is the standard form of y=(x + 7)(x + 3) (x + 1)?

Dec 14, 2015

$y = {x}^{3} + 11 {x}^{2} + 31 x + 21$

#### Explanation:

Expand or multiply the function and combine like terms

Given $y = \left(x + 7\right) \left(x + 3\right) \left(x + 1\right)$

$\implies y = \left({x}^{2} + 3 x + 7 x + 21\right) \left(x + 1\right)$

$\implies y = \left({x}^{2} + 10 x + 21\right) \left(x + 1\right)$

$\implies y = \left({x}^{3} + {x}^{2} + 10 {x}^{2} + 10 x + 21 x + 21\right)$

$\implies y = {x}^{3} + 11 {x}^{2} + 31 x + 21$