Non-linear equations and sequences

These assignments seem to be getting harder as they go on.

Hopefully, these'll be the last for a while.

Thanks again...

Solve the system of equations using any method.

logx(5y) = 3

logx(y) = 2

x=? and y=?

A rectangle has a perimeter of 72 centimeters and an area of 320 square centimeters. Find the dimensions of the rectangle.

Find the general, or nth, term of the arithmetic sequence given the first term a1 and the common difference d.

a1 = - 1, d = - 7/10.

Find the sum.

3 + 0 - 3 - ... - 75 = ...

Dr. Wesely contributes 500 from her paycheck (weekly) to a tax-deferred investment account. Assuming the investment earns 6.5% and is compounded weekly, how much will be in the account in 48 weeks?

THANKS.