Question

A family of 6 eats at an Italian restaurant.
Some order a meatball sub for $9.
Some order chicken parmesan for $11.
The total bill was $58.
How many ordered the meatball sub?

Answer 1

m = nuumber who ordered the meatball sub
c = number who order the chicken parmesan
m + c = 6
9m + 11c = 58
m + c = 6
c = 6 - m
9m + 11(6 - m) = 58
9m + 66 - 11m = 58
-2m + 66 = 58
-2m = 58 - 66
-2m = -8
m = -8/-2
m = 4