Need por favor
a group of 11 people are going to the movies one saturday. adult tickets cost $13.50 each and child tickets cost $8.25 each. if the total cost for admission to the movies is $111.75, how many children attended the movie?

4

5

6

7

K so you have to set 2 equations like this
x meaning the amount of adults
and y meaning the amount of kids

x+y=11
13.5x+8.25y=111.75

Then use substitution method and you get
x=11-y from the first equation
plug that in to the second and you get 

13.5(11-y)+8.25y=111.75
Solve for y in that equation by distributing and then combining like terms
148.5 - 13.5y + 8.25y = 111.75
148.5 - 5.25y = 111.75
Then, you need to subtract 148.5 from each side and cancel the negatives

5.25y=36.75
solve for y and you get
36.75/5.25 = 7
y=7
7 Children attended the movie.

Hope this heldped!