SOLUTION: I have been reviewing factoring trinomials. I am kind of stuck on this problem. I got an answer and it is correct according to the book, but I just want to know how to check my ans

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I have been reviewing factoring trinomials. I am kind of stuck on this problem. I got an answer and it is correct according to the book, but I just want to know how to check my ans      Log On


   

Question 422912: I have been reviewing factoring trinomials. I am kind of stuck on this problem. I got an answer and it is correct according to the book, but I just want to know how to check my answer. This all falls under factoring compleely.
b^4-3b^3-10b^2
the answer is b^2(b+2)(b-5). How do I go about checking this sort of problem? I am not sure what to do with the gcf when I am trying to check.
Thanks
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

b%5E4-3b%5E3-10b%5E2.....factor out common term b%5E2
b%5E2%28b%5E2-3b-10%29......now factor %28b%5E2-3b-10%29.....replace -3b with 2b+-5b
b%5E2%28b%5E2+%2B+2b+-5b-10%29....group first two and second two terms
b%5E2%28%28b%5E2+%2B+2b%29+-%285b%2B10%29%29......factor outb from %28b%5E2+%2B+2b%29 and
5 from %285b%2B10%29
b%5E2%28b%28b+%2B+2%29+-5%28b%2B2%29%29
b%5E2%28b-5%29%28b%2B2%29%29