Hi! Welcome to Brainly! Let's solve this word problem together below! :)
Let's write this as a system of equations.
8a+4s=880
a= s+20
Let's plug our a value into the first equation.
8(s+20)+4s=880
8s+160+4s=880
We combine like terms.
12s+160=880
We subtract 160 from both sides.
12s=720
We divide both sides by 12
s=60
Now, we plug this value into the second equation.
a= 60+20
a= 80
Therefore, 80 adult tickets were sold.
I hope this helps! Have a fabulous time here at Brainly! :)