Write an equation of the line containing the given point and parallel to the give line (8,-5); 5x-3y=7
the given line has slope 5/3, and your line must have the same slope.
So now you have a point and a slope, so use the point-slope form for a line:
y+5 = 5/3 (x-8)
you can massage that into any of several other formats.