Answer:
42 child and 70 adult
Explanation:
Let a = number of adult tickets
c = number of child tickets
a+c = 112
2.25a + 1.75c = 231
Solve the first equation for a
a = 112-c
Substitute this into the second equation
2.25(112-c) + 1.75c = 231
Distribute
252 - 2.25c +1.75c = 231
Combine like terms
252 -.5c = 231
Subtract 252 from each side
252-252 -.5c = 231-252
-.5c = -21
Divide each side by -.5
-.5c/-.5 = -21/ -.5
c = 42
Now can find a
a = 112-c
a = 112-42
a = 70