Answer:
(-4, -3)
Explanation:
Using elimination by addition and subtraction works best here.
Suppose we decide to eliminate x temporarily. To do this, we multipy the first row by 4, obtaining
-12x + 28y = -72
4x - 4y = 8
Next, multiply the second row by 3, obtaining the "equivalent system"
-12x + 28y = -72
12x - 12y = 24
Combining these equations, column by column, we get:
16y = -48. So y = -3.
Now let's find x. Substitute -3 for y in the second equation:
4x - 4(-3) = 8, or
4x + 12 = 8, or
4x = 8 - 12 = -4. This tells us that x = -4.
The solution is thus (-4, -3).