# Thread: Adding and subtracting exponents help

1. ## Adding and subtracting exponents help

Ok, I really need help with his these steps work, and what to do ect. I have no idea what to do when it comes toadying or subtracting exponents, I just know that the index, and radicands must be the same, what do I do if they are different, what do I do if there is no coefficient ct. The question is the square root of seven, minus the square root oof 28 plus 3 times the square root of 63.

2. ## Re: Adding and subtracting exponents help

Originally Posted by xXplosionZz
Ok, I really need help with his these steps work, and what to do ect. I have no idea what to do when it comes toadying or subtracting exponents, I just know that the index, and radicands must be the same, what do I do if they are different, what do I do if there is no coefficient ct. The question is the square root of seven, minus the square root oof 28 plus 3 times the square root of 63.

3. ## Re: Adding and subtracting exponents help

Originally Posted by xXplosionZz
...The question is the square root of seven, minus the square root oof 28 plus 3 times the square root of 63.
If I understand your question correctly you want to simplify

$\sqrt{7} - \sqrt{28} + 3 \sqrt{63}$

Factor (if possible) and determine partially the square-root:

$\sqrt{7} - \sqrt{4 \cdot 7} + 3 \sqrt{9 \cdot 7}$

You should come out with $8\sqrt{7}$

4. ## Re: Adding and subtracting exponents help

Thank you very much, it was the part where I had to square root the 4 and the 9, then multiply those by the coefficient which I drew a blank, and then proceed to add/ subtract.