90 I’m sorry if I am wrong I got that in paper :)
Let
x-----------> the number of kids
y----------> the number of adults
we know that
2.5x+6y=$7150---------> equation 1
x=2y-------------> equation 2
substitute 2 in 1
2.5*[2y]+6y=7150-----> 5y+6y=7150----> 11y=7150-----> y=650
x=2y----> x=2*650----> 1300
the answer is
the number of kids is 1300
As it has a maximum value the coefficient of x^2 will be negative
The vertex will be at (-8,2) so in vertex form it is
y = a(x + 8)^2 + 2
and as it passes through (-7,-1) we have:
-1 = a(-7+8)^2 + 2
-1 = a + 2 so a = -3
answer is y = -3(x + 8)^2 + 2
in standard form this is y = -3x^2 -48x - 190
