Question

Did I do number 4 correctly?

Answer 1

The photo is not clear. nobody can see it.

Answer 2

No, you did it incorrectly. The answer is y=-3
How I did this was;
2y+x=-15 x=3y
2y+3y=-15
If you multiply a whole number by a negative number you get a negative number, so I found a, number that could be multiplied into two different numbers that cloud be added together to have a sum of -15.
I really hope that made sense.