# How do you solve the following system?: 3x+3y=-21 , 4x-y=-1

$y = 4 x + 1 \to 3 x + 3 \left(4 x + 1\right) = - 21$
$3 x + 12 x + 3 = - 21 \to 15 x = - 24 \to x = - \frac{8}{5} , y = - \frac{27}{5} = \left\{- \frac{8}{5} , - \frac{27}{5}\right\}$