Explanation:
to solve for y means to transform the equation into a form so that we get
y = ...
or
... = y
always remember, whatever change you apply to one side of the equation, you need to apply it also to the other side (otherwise you are destroying the original equality information).
so,
5x - 8y = 17 | we add 8y to both sides
5x = 8y + 17 | we subtract 17 from both sides
5x - 17 = 8y | we divide both sides by 8
(5x - 17)/8 = y
nobody can "solve" a single equation with more than one variable to a single numeric result.
there are infinitely many numeric solutions, as for any y-value we can think of, there is an x-value that is "causing" it. and we can think of infinitely many y-values.
we would need a second equation in x and y that allows us to constraint either x or y to find specific numeric solutions.