# How do solve the following linear system?:  3x – 2y = 7 , 9x + 6y = -2 ?

Mar 24, 2018

$x = \frac{19}{18}$ $y = - \frac{23}{12}$

#### Explanation:

You can solve them by adding or subtracting the equations

On multiplying the first equation by 3, we get $9 x - 6 y = 21$
On adding this to $9 x + 6 y = - 2$ , we get $18 x = 19$

So, $x = \frac{19}{18}$ to find y, we put this back into one of the equations

$3 \cdot \left(\frac{19}{18}\right) - 2 y = 7$

$3 \cdot \left(\frac{19}{18}\right) - 7 = 2 y$

$\frac{19}{6} - 7 = 2 y$

$\frac{19 - 7 \cdot 6}{6} = 2 y$

$y = - \frac{23}{12}$