Answer:
x = 4, y = 9.
Step-by-step explanation:
3x -2y = -6 and y = x+5
Substitute y = x + 5 in the first equation:
3x - 2(x + 5) = -6
3x - 2x - 10 = -6
x = -6 + 10
x = 4
So y = 4 + 5 = 9.
I'm sorry but the solution you proposed was a bit hard to follow, so I'll just post my solution: we convert "2 and 1/2" to a single fraction:

So, we know that 5/2 gallons cost 60 dollars, which means

To find the cost of a single gallon, we have to solve the equation for g:

Well.. divide 90 into 60, so 1.5 this means 1.5 hours, and then add it to 1:30 which is = 3:00 o'clock
The initial equation is:

Let's transform it for x:

... distract 5:

... divide both sides by 5: