Help?!?! Fan and Medal. Equation is posted below

Question

anonymous · Answer

im ready

anonymous · Answer

$$x \sqrt{5} + 3x \sqrt{2} + 9y \sqrt{7} + 3y \sqrt{7} $$

anonymous · Answer

whoa

anonymous · Answer

idk about that

alexandervonhumboldt2 · Answer

you can only combine 9y sqrt7 with 3y sqrt7

brrandyn · Answer

First, evaluate what you can. 
x√5+3x√2+12y√7...

alexandervonhumboldt2 · Answer

just add $$9y \sqrt7 + 3y \sqrt7=(9y+3y)\sqrt7=?$$

anonymous · Answer

Alright. I can help.  :D
First, let's go over some rules:
We cannot combine any terms with fractions UNLESS they have the same terms under the square root. So, the first two terms can't be combined with anything. However, the last two can be combined (added), since they both have a 7 under the square root:
To add those terms, you simply add the coefficients of the terms (numbers and variables in front of the square root). Therefore, we have:
$$9y + 3y= 12y$$
That will be the coefficient of the combined term. The square root term will stay  the same.  The first two terms were not changed. To put it all together, we have:
$$x \sqrt{5} + 3x \sqrt{2} + 12y \sqrt{7}$$

anonymous · Answer

That will be your answer.   :D