H = cost of horseback riding per hr, p = cost of parasailing per hr 3h + 2p = 192...multiply by 2 2h + 3p = 213..multiply by -3 ------------------ 6h + 4p = 384 (result of multiplying by 2) -6h - 9p = - 639 (result of multiplying by -3) -----------------add -5p = - 255 p = -255/-5 p = 51 <== cost of 1 hr for parasailing
3h + 2p = 192 3h + 2(51) = 192 3h + 102 = 192 3h = 192 - 102 3h = 90 h = 90/3 h = 30 <== cost of 1 hr of horseback riding