Answer:
a = 195 ; c = 615
Step-by-step explanation:
So, you want to start by forming your equations...
I will use 'c' for children and 'a' for adults for my variables
3a + 30 = c
(this is because of the info that 30 more tickets than 3 times the amount of children's were sold than adult)
then for equation 2:
3c + 5a = 2820
(this is because of the prices of the tickets and the total money raised)
Then, plug in the equation for c
Your equation should look like:
3(3a + 30) + 5a = 2820
You get:
(9a +90) + 5a = 2820
Then:
14a = 2730
So:
a = 195 adult tickets sold
Plug in a, to find c:
3 (195) + 30 = c
585 + 30 = c
c = 615 children tickets sold