A. Just write an expression:

That's your answer.
B. Simplify the above expression to get:

So your answer would be, "He had $132.63 left in his account."
I think its 7x since x represents the hours she worked. So lets say that she worked for 5 hours this day. It would be 5*7 which is $35. So it is 7x and if there is any choices you might say it as well so we can help you better
I hope this helps you
5000.pi=4/3.pi.r^3
r^3=3750
r=15,53
Surface Area=4pir^2
Surface Area =4.pi. (15,53)^2
Surface Area =964,72.pi
Could you give the question more clear?