Yup... the way Point has done it is generally the most effective way to solve these sorts of problems.
However I got y = (3/5)x - 2 ... minus 2!
It always helps to use a method where you deal with as little negatives as possible!
Because you got 3x - 5y = 10
3x = 10 + 5y (bring the 5y over, get rid of all the negatives)
3x - 10 = 5y (move the 10 to the other side - negative is unavoidable - to isolate the 5y)
(3/5)x - 2 = y (divide through by 5 to get the function of y.)
I think you just put in the wrong sign Point.
Simply make the equation as a function of
y (That is, have it as y = ...)
As a side note, it always helps to know general formula's too.
You (should

) know the general equation of a straight line is
y = mx + c
Where: m = gradient of the line
x = your variable
c = a constant, and also where the line crosses the y-axis.