Answer:
x is equal to four, and y is equal to negative eight.
Explanation:
Let's solve it rearranging the first equation to define y:
9x + y = 28
y = 28 - 9x
Now we plug it in to the second equation:
3x + 3y = -12
3x + 3(28 - 9x) = -12
And solve for x:
3x + 84 - 27x = -12
-24x = -96
x = 4
Now we can plug that x value into one of the original equations to find the value of y
9x + y = 28
36 + y = 28
y = 28 - 36
y = -8
Let's test our answer by plugging that y value into the other equation, and seeing if we get the same x value:
3x + 3y = -12
3x + 3(-8) = -12
3x - 24 = -12
x - 8 = -4
x = 4
So we know our answer is correct.