You don’t know how many adults were there and how many students were there.
But,
$8(adults) + $5(students) = $19060
And,
Adults + Students = 2570
Let A = adults and S = students
8A + 5S = 19060
A + S = 2570
This is called a system of equations. To solve, you need to rearrange both equations to solve for one of the variables, you can pick any. This makes them cancel out so you can focus on 1 variable. After solving, you can plug the solved variable back into any of the given equations and solve for the second one.
S = 19060/5 - 8A/5
S = 3812 - (8A/5)
This is the first equation rearranged to solve for S
Second:
A + S = 2570
S = 2570 - A
Now, equal each other
3812 - (8A/5) = 2570 - A
Solve for A
3812 + A = 2570 + 8A/5
19060 + 5A = 12850 + 8A
19060 - 12850 = 3A
6210 = 3A
2070 = A
There were 2070 adults
Now, plug A back into any of the 2 equations and solve for S
A + S = 2570
2070 + S = 2570
S = 2570 - 2070
S = 500
2070 adult tickets were sold
500 student tickets were sold