Answer:
(x,y)=(24,-28)
Step-by-step explanation:
1. Multiply both sides by -1
3x+3y=-12
-4x-3y-=-12
2. Elimnate one variable by adding the equations
-x=-24
3. Change the signs
x=24
4. Susbstitue the value of x in the equation 3x+3y=-12
3 x 24 + 3 y = -12
y=-28
5. Check the solution by plugging in the values.
(x,y)=(24,-28)
