Hi Elisabeth,

You can certainly solve the problem with the two variables $x$ and $y.$ You then have two equations. Since the sum is -8 you know that $x + y = -8.$ The difference is 4 so write this as an equation also and solve the resulting two equations for $x$ and $y.$

I would however prefer to approach the problem this way. Let $x$ be the greater of the two numbers. Since their difference is 4 you know the second number is 4 less than $x$ so it is $x - 4.$ The sum of the two numbers is -8 so $x + x - 4 = -8.$ solve for $x.$

Penny