Area = 15x^3 + 25x^2 what is the length and width of the rectangle?

Answer 1

no unique answer.

any pair of factors of 15x3 + 25x^2 would do

15x^3 +25x^2 = x^2(15x + 25)
or
= 5x(3x^2 + 5x)
or
= 5(5x^3 + 5x^2)

etc

for any answer, the two factors would be the length and width