David M. answered 11/30/20
Dave "The Math Whiz"
You have 2 unknowns so you need to find 2 equations to solve this.
Let x = number of adults that attended
y = number of children that attended
Eq. I: x + y = 87
Eq. II: 3x + 2y = 208
We can use either the elimination or substitution method to solve this. Let's use the substitution method. Using Eq. I we can rearrange it to find out x is in terms of y:
x + y = 87
x = 87 - y
Using this value for y in Eq. II we can solve for y:
3x + 2y =208
3(87 - y) + 2y =208
261 - 3y + 2y = 208
261 - y = 208
-y = 208 - 261
-y = -53
y = 53
Using this value of y in either Eq. I or II we can solve for x:
Eq. I: x + y = 87
x + 53 = 87
x = 87 - 53
x = 34
Therefore, the number of adults was 34 and the number of children was 53.
Hope this helps!