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.

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):

I used Microsoft math to get the answer,

.

However, I've yet to figure out how to reach that answer. I'm guessing that saying:

won't really cut it.

(b):

Same as above, I used Microsoft math to get the final answer, but have not quite worked out how to reach said answer:

.

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!