What’s the answer (only answer if you know)

First, it says to simplify the expression, so you should try that first.

Simplified Expressions:
8y^15 and 36y^7

Then compare on which simplified expression has the greater exponent
8y^15 and 36y^7
8y^15 has the greater exponent

8y^15 = (y^9)(2y^2)^3 (Or the first expression)

The exponents of expression #1 are greater than the exponents of expression #2