Coordinate Geometry Problem!!!

[akshatgupta87]

Q.) Lines n and p lie in xy plane. Is slope of line n less than slope of line p?
a. Lines n and p intersect at (5, 1)
b. Y-intercept of line n is greater than y intercept of line p

Someone please explain...

Thanks,
Akshat

[Frankenstein]

Hi,
If m is the slope and c is the y-intercept, equation of the line is y=mx+c
Let the equations of lines n and p be y = ax+b and y=cx+d
From(1):
n and p intersect at(5,1).
So, 1=5a+b => a = (1-b)/5
and c = (1-d)/5
Not sufficient
From(2):b > d
Not sufficient

Both(1)&(2): b>d So, -b<-d
So,(1-b)/5 < (1-d)/5
So, a < b
Sufficient

Hence, C