Question

three times a first number minus a second number equals negative forty The first number plus twice the second number equals negative forty

Answer 1

2x-y=-40
x+2y=-40
Multiply the second equation by 2
2x+4y=-80
Subtract
2x-y=-40
2x+4y=-80
-5y=40
Decide by -5
y=-8

To find y, plug it back into an equation
x+2y=-40
x+2(-8)=-40
x-16=-40
x=-24