If the speed on the first part of the trip is given by "s", then the total time in hours can be computed as 57/s + 21/(s-5) = 2 Multiplying by s(s-5), we get 57(s-5) + 21s = 2s(s-5) Subtracting the left side from both sides, we get 0 = 2s^2 - 10s - 57s + 57*5 - 21s 0 = 2s^2 - 88s + 285 Using the quadratic formula, you find the solution to be s = (-(-88) + √((-88)^2 - 4(2)(285)))/(2(2)) s = (44 + √1366)/2 s ≈ 40.480 mph The first part of the trip was completed at 40.480 mph, and the second part was completed at 35.480 mph. _____ Check 57/40.480 + 21/35.480 ≈ 1.408 + .592 = 2.000 The canoe was not being paddled at that speed.
