whenever you see this kind of question you don't need to start doing all the expressions, but look at the first and last numbers of the answer, the ones that cannot be changed (have no x or y or have those that cannot be changed in this expression):
the answer can't be a or c because in the given expression we can find 3x²y² and that's the only number where we can find x²y², so it cannot be changed. (you'll have 3x²y² in the answer)
now let's look at the last digit, that doesn't have a x or a y:
in b and d we can find 2 different results so this can determine which answer is correct:
let's look back at the given expression: -7+4= -3
so the answer is b
