Two square roots of 25. why is there only one answer for the radius of the button?

Select the correct answer from the drop-down menu. subtracting 3xy^2 from 8xy^2 gives the same result as the expression. [tex]3xy ^{2} - 8xy ^{2} [/tex][tex] { - 7xy}^{2} - {2xy}^{2} [/tex][tex] {7xy}^{2} - {2xy}^{2} [/tex]

Precalculus question, image attached.

The expression 1.01*1.005(^t) gives the amount of money, in thousands of dollars, in carter's savings account (t) years after he opens it. what does 1.01 represent in this expression?