Answer:
x = 5, and y = 8
Explanation:
You can solve this system by solving either of the equations for either x or y, and substituting that into the other.
Since the first equation is already defined for y, let's substitute that into the second equation:
4x - 5y = -20
4x - 5(3x - 7) = -20
4x - 15x + 35 = -20
4x - 15x = -20 - 35
-11x = -55
x = 5
We can then plug that into either of the original equations to find y:
y = 3x - 7
y = 3 * 5 - 7
y = 15 - 7
y = 8
We can also verify our answer by plugging one of the values into either of the original equations and seeing what we get:
4x - 5y = -20
4x - 5 * 8 = -20
4x - 40 = -20
4x = 20
x = 5
So we know the answer is correct. x is equal to five, and y is equal to eight.