Answer:
adults=31, children = 108
Step-by-step explanation:
a + c = 139 equation 1
10a + 8c = 1174 equation 2
a=139-c isolate a from equation 1
10(139-c) + 8c = 1174 substitute a value into equation 2
1390-10c + 8c = 1174
-2c = -216
c = 108
use value of c in either equation to find value of a
a + c = 139
a + 108 =139
a = 31
