Answer: -2y^2+7y-4
Step-by-step explanation:
Combine -5y^2 and 3y^2 to get -2y^2.
Combine 5y and 2y to get 7y.
Combine -5, 2, and -1 to get -4.
Put these in order with the highest exponent first.
-2y^2+7y-4