You mean the linear equations, 5x-y+1=0,4x-y+1=0 the slopes are 5 and 4 respectively. it is clear that slope of first equation is greater that is it has a steeper graph therefore it Will always be greater than the other for x > 1 the same can be done by calculus; differentiation.
note y=5x+1 is always greater than y=4x+1 for all x>1
