Alice bought    of a pound of grapes and ate    of a pound.  how many pounds were left?

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?

7+(3n++8) what is the answer to this?

|z| > (1/2) {-1/2, 1/2} {z|(-1/2) < z < (1/2)} {z|z < (-1/2) ∪ z > (1/2)}