Question

2.5x + y = -2 ; 3x + 2y = 0

Answer 1

Looking at this, I think the easiest (personally) way to solve it would be using the Substitution method.
Meaning we have to rearrange ONE equation, to make ONE variable ( x or y) the subject.
(1)  2.5x + y = -2
(2)  3x +2y = 0

The first equation is the easiest to rearrange. Make Y the subject for (1).
Thus,
y = -2.5x - 2
Substitute this into equation (2).
∴ 3x + 2(-2.5x - 2) = 0
Expand and simplify:
3x - 5x - 4 = 0
∴ -2x - 4 = 0
Making x the subject:
-2x = 4
x = -2
From here, we need to substitute x=-2 into equation (1) or (2) to solve for the y-value. I would say the easiest way, would be to rearrange one, to make y the subject, which was what we did earlier.
Thus,
y = -2.5x - 2
y = ((-2.5(-2) -2)
y = 3
(X,Y) x = -2, y = 3
Answer: (-2,3)

I hope you followed through.