3 adults and 5 kids.
You can get this by setting up the following system of equations.
x + y = 8 (number of people)
10x + 12y = 86 (cost)
If all angles are equal it must be an equilateral triangle which means the measure of Y is 60°
A line parallel to your equation has the same slope, so it should be in the form:
y = (-3/2)x + b
To figure what "b" has to be, plug in the point (4,0) and solve:
0 = (-3/2)*4 + b
0 = -6 + b
6 = b
So the equation of the line is:
y = (-3/2)x + 6
B!
hope this helps, it just seems like the best answe.