I'm struggling with this problem and can't find a good example in my book of how to solve.

solve for y
y-1/x-0=-3

thanks in advance

Your question is typed in an ambiguous way

is it (y-1)/(x-0) = -3

why would any textbook write x-0 as a denominator?

I will take it at face value, the way you typed it.

y - 1/x - 0 = -3
y - 1/x = -3
multiply by x
xy - 1 = -3x
xy = 1 - 3x
y = (1-3x)/x