For this case we propose a system of equations:
x: Let the variable representing the number of children in the concert
y: Let the variable representing the number of adults at the concert
According to the assistance we have:

According to the cost we have:

Substituting the first in the second equation we have:

Thus, the concert was 375 adults.
On the other hand we have:

Thus, the concert was 1125 children.
In total they were:
people
ANswer:
The concert was 1500 people
U have to times by 2 it will it will change
Answer:
11 inches
Step-by-step explanation:
A rectangle's perimeter can be found using:
p=2l+2w
We know that the perimeter, p, is 58, and the length/height is 18. Therefore, we can substitute those values in
58=2(18)+2w
Multiply 2 and 18
58=36+2w
Since we want to find the width, we need to get w by itself. First, subtract 26 from both sides
58-36=36-36+2w
22=2w
Since w is being multiplied by 2, divide both sides by 2. This will cancel out the 2, and leave w by itself.
22/2=2w/2
11=w
So, the width is 11 inches