SOLUTION: Homework help needed - sqrt 5a+ 2sqrt45acube The answer in the back of the book is (1+6a)sqrt5a; however, I cannot get it to work out to this answer.

Algebra ->  Radicals -> SOLUTION: Homework help needed - sqrt 5a+ 2sqrt45acube The answer in the back of the book is (1+6a)sqrt5a; however, I cannot get it to work out to this answer.      Log On


   

Question 145228: Homework help needed -
sqrt 5a+ 2sqrt45acube
The answer in the back of the book is (1+6a)sqrt5a; however, I cannot get it to work out to this answer.
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
sqrt%285a%29%2B+2sqrt%2845a%5E3%29
= sqrt%285a%29%2B+2sqrt%285a%2A9a%5E2%29
= sqrt%285a%29%2B+2sqrt%285a%29%2Asqrt%289a%5E2%29%29
= sqrt%285a%29%2B+2sqrt%285a%29%2A3a%29
= sqrt%285a%29%2B+sqrt%285a%29%2A6a%29
= %281%2B+6a%29%2Asqrt%285a%29%29
The book is right. I have seen the book be wrong, but it's rare.