1. 0 - 34 + 13 - 5 = -26.....26 ft below the surface
2. y = 15x + 50 220 = 15x + 50 220 - 50 = 15x 170 = 15x 170/15 = x 11 1/3 = x......he worked 11 1/3 hrs.......not sure about this...because it does not specify how many visits he made...but if this was just for 1 visit, then he worked 11 1/3 hrs
