# How do solve the following linear system?:  3x + 4y = -2 , 3x + y = -20 ?

Jan 21, 2016

$3 x + 4 y = - 2. \ldots \ldots \ldots \ldots \ldots . . \left(i\right)$
$3 x + y = - 20. \ldots \ldots \ldots \ldots \ldots \left(i i\right)$

Subtracting (ii) from (i) we get

$3 y = 18$
$\implies y = 6$

Put $y = 6$ in $\left(i\right)$

$\implies 3 x + 4 \left(6\right) = - 2$

$\implies 3 x + 24 = - 2$
$\implies 3 x = - 26$
$\implies x = - \frac{26}{3}$