for b, 5y=4+3x. we can divide that by 5 to get y=4/5+3/5x, where the slope is 3/5x. for c, 5y-3x=-1, so we add 3x to each side to get 5y=3x-1. when we divide each side by 5, we get y=3/5x-1/5. the slopes in B and C match up (3/5), so lines B and C would evidently be parallel since the slope is the same and they never touch.
