I need help getting the answer

Which expressions are equivalent to the one below? check all that apply. 25x/5x a. 5x b. 5 c. 5x•5x/5x d. 25x e. (25/5)^x f. (25-5)^x

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (-1+i)+(21+5i)+0

Adecorative window is made up of a rectangle with semicircles at either end. the ratio of ad to ab is 3: 2 and ab is 30 inches. what is the ratio of the area of the rectangle to the combined area of the semicircles? possible answers: a. 2: 3 b. 3: 2 c. 6: π d. 9: π e. 30: π