The average speed of the canoe is 5 1/4 in kilometers per hour
I)
8 - 3x = 23
-3x = 15
x = -5
ii)
5x - 16 = 34
5x = 50
x = 10
iii)
2 - 5x = -3
-5x = -5
x = 1
Dr /dt = 7
A = pi r^2
dA / dr = 2pir
dA/dt = dA/dr * dr/dt = 2pir * 7 = 14pir
when r = 12 rate of change of the area = 14*pi*12 = 168pi
= 527.79 cm^2 / minute to nearest hundredth
