# How do you solve 3x + 3y = –6 and –x + y = 0?

Aug 4, 2015

The solution for the system of equations is:
color(blue)(x=-1,y=-1

#### Explanation:

 3x+3y=–6 .....equation $\left(1\right)$

–x+y=0
x=color(blue)(y........equation $\left(2\right)$

Solving through substitution:

Substituting equation $2$ in equation $1$
 3x+3y=–6

 3 * color(blue)(y)+3y=–6

 6y=–6

 color(blue)(y=–1

From equation $2$ we know that : $x = y$
So , color(blue)(x=-1