Can you please help me answer this question and explain how you figured it out.

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

Solve the following pair of equations for x and y: ax/b_ by /a= a +b; ax - by = 2ab

Arational number that is equivalent to -20/4?