Answer:
d) 125z^2
Explanation:
A perfect square is a number gotten by square an integer e.g. 4 = 2^2, 9 = 3^3. So, 4 and 9 are perfect squares.
lets take each option
a) 49x^2 = 7^2 * x^2 This is a perfect square
b) 64a^2 = 8^2 * a^2 This is a perfect square
c) 121y^2 = 11^2 * y^2 This is a perfect square
d) 125z^2 = (10^2 + 5^2) * z^2 This is not a perfect square