a = number of adult tix = 230
c = number of child tix = 160
a + c = 390 for number of tickets sold
5a + 2c = 1470 for money earned
First we’ll solve for c in terms of a
c = 390-a
Then we’ll substitute that expression in to solve for a numerical value for c:
5a + 2c = 1470
5a + 2(390 - a) = 1470
5a + 780 -2a = 1470
3a = 690
a = 230
Then we’ll drop that into the first equation to get a numerical value for c
c = 390 - a
c = 390 - 230
c = 160
Check the math:
5a + 2c = 1470
5(230) + 2(160) =
1150 + 320 = 1470