Answer:
3 adult and 2 child tickets were purchased
Explanation:
let a be the number of adults and c the number of children , then
a + c = 5 ( subtract a from both sides )
c = 5 - a → (1)
150a + 50c = 550 → (2)
substitute c = 5 - a into (2)
150a + 50(5 - a) = 550
150a + 250 - 50a = 550
100a + 250 = 550 ( subtract 250 from both sides )
100a = 300 ( divide both sides by 100 )
a = 3
substitute a = 3 into (1)
c = 5 - 3 = 2
there were 3 adult and 2 child tickets purchased