Answer:
25y^4
Step-by-step explanation:
5^2y^4
5^2 is the same as 5x5, because you're multiplying 5 by itself twice, so 5^2 is 25. you can't figure out what y^4 is because y is just a variable ad we don't know what number it represents, therefore it stays the same.
so the answer is 25y^4
