Answer:
y=-5
x=2
Step-by-step explanation:
3x + 3y=-9
3x - 3y=21
-
0+6y=-30
6y=-30
y=-5
3x-15=-9
x=2
Answer:
[tex]\large\boxed{x=2,\ y=-5\to(2,\ -5)}[/tex]
Step-by-step explanation:
[tex]\underline{+\left\{\begin{array}{ccc}3x+3y=-9\\3x-3y=21\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad\qquad6x=12\qquad\text{divide both sides by 6}\\.\qquad\qquad\boxed{x=2}\\\\\text{Put the value of x to the first equation}\\\\3(2)+3y=-9\\6+3y=-9\qquad\text{subtract 6 from both sides}\\3y=-15\qquad\text{divide both sides by 3}\\\boxed{y=-5}[/tex]
