Can someone tell me how to solve my problem? Do I just start plugging in numbers or is there some rational to figure this out?

Question

Sum of three numbers is -5. First, minus second, plus 4 times the third is -20. The third plus 4 times the first plus the second is -20.

Answer 1

a + b + c = -5
a - b + 4c = -20
4a + b + c = -20

looks like a very simple 3 equation in 3 variables question.

Hint: add the first two, then the last two, and go from there

I got a=-5
b=3
c=-3

Answer 2

The sum of two two numbers is(3). Three times the first number minus the second number equals 27. What are the two numbers

Answer 3

(-6) 24