Factor out the greatest common factor. If the greatest common factor is 1, just retype the polynomial. 30u^5–45u^3

why stop there?

5u^3(6u^2 - 9) = 15u^3(2u^2 - 3)

You are correct! Thank you for pointing that out. The complete factored form is 15u^3(2u^2 - 3).

5u^3(6u^2 - 9)