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

$y = {x}^{2} + 10 x + 21$
$y = \left(x + 7\right) \left(x + 3\right)$
$y = \left({x}^{2} + 7 x + 3 x + 21\right)$
$y = {x}^{2} + 10 x + 21$