Hi I need help can someone simplify this?

Write a numerical expression that satisfies all of the following conditions. 1.)the only number used in the expression is 5 2.)at least one exponent other than 1 is used 3.)when the expression is evaluated, the answer is greater than 40 and less than 50

The function show two sisters' savings account and the rate at which they plan to deposit money

Solve the formula ax+ by = c for x.