# adding and subtracting radicals and fractions

• Apr 3rd 2007, 04:04 PM
Cait
I think they are radicals anyway >_> heres some probs from my HW that i didnt get.
Code:

``` 11. *figured it out* 31. *figured out* 41. Find LCD  9                  3 ---    and    --- 8x              2x+4 answer: 8x(x+2) 59.  9        (blank) ---  =    ----- x+3      2(x+3) and 63.   x                        (blank) -----            =        ----- x^2+6x+8        (X+4)(X+2)(X+1)```
Hopefully those will format correctly..

anyway.

My book does a horrible job of showing how to do these.. -__-.. and purple math doesnt help me much either.

Thanks so much
~Cait
• Apr 3rd 2007, 06:42 PM
Jhevon
Quote:

Originally Posted by Cait
bump? plz! this shouldnt be that hard!

you are right for 41.
• Apr 3rd 2007, 06:44 PM
Cait
..I know those answers are right i got em out of the book!

What i need is how they GOT those answers lol.
• Apr 3rd 2007, 06:45 PM
Jhevon
59.

9/(x+3) = 9/(x+3) * (2/2) = 2*9/2(x+3) = 18/2(x+3)

so the blank is 18

notice that we had a fraction where the denominator increased by a factor of 2. to maintain equality, that is, to keep the fraction at the same value it was before, the numerator also had to increase by factor of 2
• Apr 3rd 2007, 06:50 PM
Jhevon
Quote:

Originally Posted by Cait
..I know those answers are right i got em out of the book!

What i need is how they GOT those answers lol.

o ok, sorry, i thought you came up with that. ok here's how:
• Apr 3rd 2007, 06:57 PM
Jhevon
Here's 63