Hello, here is the solution:
y= 19-5/2x
2) according to the meaning of the question, y must be greater than or equal to 0, so x is less than or equal to 7, y must be an integer, so x must be an integer multiple of 2.
When x= 2 4 6
y= 14 9 4
Because a *** 12 car, when x=2, y= 14 is already greater than 12, so it does not meet the question.
When x=4
Y=9 doesn't match either.
So finally x=6 y=4 is satisfied.
So a 6 b 4 c 12-4-6=2 cars.