What is the answer for (-2)/3+(-5+8)/3

Can some one me with these questions

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

Someone answer asap for ! michele pushes a box d meters across a floor. she uses a force f, in newtons, to push the box. she pushes the box for t seconds. the formula p = fd/t calculates the power, p, in watts, that it takes for michele to complete the task. solve the formula for d.