At the movie theatre, child admission is $5.10 and adult admission is $9.00 . On Monday, 163 tickets were sold for a total sales of $1088.70 . How many adult tickets were sold that day?

Respuesta :

a = adult tickets

c = child

c + a = 163 tickets total

rewrite as c = 163-a

5.10c + 9.00a = 1088.70

5.10(163-a) + 9.00a = 1088.70

831.30-5.10a + 9.00a = 1088.70

831.30 +3.9a = 1088.70

3.9a = 1088.70-831.30

3.9a  = 257.40

a = 257.40 / 3.9 = 66

 66 adult tickets were sold