13 pts 3. mr. sanchez’s class sold fruit pies for $1.65 each and mr. kelly’s class sold bottles of fruit juice for $1.36 each. together, the classes sold 79 items and earned $118.17 for their school. (a) write and solve a system of equations that model the problem. show all your work. (b) which class earned more money? (c) how much more money did that class earn?

S = Sanchez's class, k = Kelly's class

s + k = 79s = 79 - k
1.65s + 1.36k = 118.17

1.65(79 - k) + 1.36k = 118.17
130.35 - 1.65k + 1.36k = 118.17
-1.65k + 1.36k = 118.17 - 130.35
-0.29k = - 12.18
k = -12.18 / -0.29
k = 42 <=== Kelly's class sold 42 bottles of fruit juice

s + k = 79
s + 42 = 79
s = 79 - 42
s = 37 <=== Sanchez's class sold 37 fruit pies

(b) Kelly's class earned : 42(1.36) = 57.12
     Sanchez's class earned : 37(1.65) = 61.05
     therefore, Sanchez's class earned more money

(c) Sanchez's class earned (61.05 - 57.12) = $ 3.93 more