How do you work this out?

What is the value of the expression below? (81^2)^1/8

Solve the equation below: (x+4)/6x=1/x a. x=2 b. x=0,2 c. x=-2 d. x=0,-2

Rob spent 25%, percent more time on his research project than he had planned. he spent an extra h hours on the project. which of the following expressions could represent the number of hours rob actually spent on the project? two answers