Tickets to the movies are $7 for adults and $4 for children. If 272 ticketssold $1694, then how many of each type were sold?
+36916 a = adult tix value = $ 7a
c = children = (272-a) value = $ 4 ( 272-a) summed , they equal 1694
7a + 4 (272-a) = 1694
solve for a then c = 272-a
