Answer:
28%
Step-by-step explanation:
<span>y-intercept when x = 0
</span>so
y = -7x + 1
y = -7(0) +1
y = 1
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