Answer:
120 $12 tickets and 180 $15 tickets
Step-by-step explanation:
Given the 2 equations
12x + 15y = 4140 → (1)
x + y = 300 ( subtract y from both sides )
x = 300 - y → (2)
Substitute x = 300 - y into (1)
12(300 - y) + 15y = 4140 ← distribute and simplify left side
3600 - 12y + 15y = 4140
3600 + 3y = 4140 ( subtract 3600 from both sides )
3y = 540 ( divide both sides by 3 )
y = 180
Substitute y = 180 into (2)
x = 300 - 180 = 120
Number of $12 tickets : 120 ; Number of $15 tickets : 180
