Originally Posted by

**MathBlaster47** Here are some questions that I have been struggling with for quite some time, mostly because I don't understand how to begin to work them out.

1:

Simplify if possible. If the expression cannot be simplified, write "not possible" as the answer.

$\displaystyle \frac{\sqrt{5}+1}{\sqrt{5}-1}$

I'm leaning toward not possible with this one, but it doesn't hurt to make sure.

2:

Solve for the unknown and check your work.

(a):

$\displaystyle \sqrt{y}+\sqrt{y+7}=7$

I used Microsoft math to get the answer, $\displaystyle y\approx9$.

However, I've yet to figure out how to reach that answer. I'm guessing that saying:$\displaystyle \sqrt{y}=7-\sqrt{y+7}$ won't really cut it.

(b):

$\displaystyle \sqrt{x+11}=\sqrt{x}+1$

Same as above, I used Microsoft math to get the final answer, but have not quite worked out how to reach said answer: $\displaystyle x=25$.

From looking at it I can see why 25 is the answer, but I don't think anyone would accept "it looks like 25 is a good answer"--even if I'm correct.

Thank you!