Answer:
250 adult tickets and 150 children's tickets
Explanation:
x=number of adult tickets
y=number of children tickets
8x+5y=2760
x+y=400
Multiply the second equation by 8
8(x+y=400)
8x+8y=3200
8x+5y=2750
8x+8y=3200
Subtract
8x-8x=0
5y-8y=-3y
2750-3200=-450
-3y=-450
Divide by -3 on both sides
y=150
Go back and insert y into any of the equations
x+150=400
Subtract
400-150=250
x=250
There are 250 adult tickets and 150 children's tickets.