47. Divide each side by one half times h. Then subtract b1 from each side. You'll get A/(1/2h)-b1=b2. (A divided by 1/2h - b1 =b2)
50. Divide each side by one half times s. Then subtract s squared from each side. You'll then get V/(1/2s)-s^2=h. (V divided by 1/2 times s - s^2 = h)
