18. One ticket for a school play costs Php 4.00 if it is bought in advance and Php of 5.50 as
the door prize. The total ticket sale was Php 440.00. Let x stands for the number of
advance tickets sold and y for the number of tickets sold at the door. Write an equation
that relates x and y
A. 4x + 5.50y = 440
B. 4x - 5.50y = 440
C. 5.50 x + 4y = 440
D. 5.50 x - 4y = 440​