28. The sides of a rectangle are ( x + 2 ) cm and ( y - 3 ) cm. What is the area ? A=lw
29.) A triangle has a base of {x}^{2} - \: 7x \: + \: 11x 2 −7x+11 and a heigth of 4x . what is thr area of the triangle ? a = \frac{1}{2} bha= 2 1 bh
30.) A car traveled (2 {b}^{3} \: + \: 3 {b}^{2} \: - 4b \: + \: 1(2b 3 +3b 2 −4b+1 km in (2b-1) hour . What is the average of speed of the car ? average speed = \frac{distance \: trvelled}{time \: take} timetake distancetrvelled
