Lowest common denominator of the following denominators: (5x^3)+25x^2 and 3x+15

Answer 1

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

so the LCD = 3(5x^2)(x+5)
or
15x^2(x+5)