Question

I need help i dont understand this​

Answer 1

140 tickets sold at the door

Step by Step Explanation:

x = tickets sold in advance
y = tickets sold at the door

We use the formula ax+by=c and a+b=c

x + y = 514
17x + 20y = 9158

y = 514 - x
17x + 20(514 - x)
17x + 10,280 - 20x = 9,158
-3x + 10,280 = 9,158
-3x = -11222
x = 374

This is for tickets sold in advance so we need to find y

374 + y = 514
y = 140

140 tickets were sold at the door