# How do solve the following linear system?:  3x + 2y = 12, 3x - y = -6 ?

Nov 24, 2015

Elimination or substitution method

#### Explanation:

Using substitution method

From eq(2)
$y = 3 x + 6$
Substitute in eq(1)
$3 x + 2 \left(3 x + 6\right) = 12$
$9 x + 12 = 12$
$9 x = 0$
$x = 0$
$y = 3 \cdot 0 + 6$
$y = 6$

Using elimination method
$3 x + 2 y = + 12$
$3 x - 1 y = - 6$
Subtract these 2
$3 y = 18$
$y = 6$ Use this in any one equation to get $x = 0$