A boat travelled 60km downstream in 4 hours and the return trip in 5 hours. What is the speed of the boat in still water?
km/h Write your answer to the nearest tenth.

Determine whether the quadrilateral below is a parallelogram. justify/explain your answer (this means back it up! give specific information that supports your decision. writing just "yes" or "no" will result in no credit.)

There are 15 plates and each plate is either 7 or 12 inches diameter. which systems of equations do you use to find the number of 7 inch plates, x and 12 inch plates, y

Which shows the correct solution of the equation 1/2a+2/3b=50, when b=30?