(B) as well... I agree with what
vshaunak@gmail.com said above
For 2 equations of line, we have 3 possible cases:
> 1 point intersect the 2 lines = 2 different slopes for the lines
> No intersection = Same slopes and different Y-interceptors
> Infinite number of interesections = Same slopes and same Y-interceptors
So, the question just asks us for which value of k, the slopes are equal.
o 3x+4y = 12
<=> y = -3/4 * x + 12
o kx+12y = 30
<=> y = -k/12 * x + 30/12
By equalizing the 2 slopes, we have:
-k/12 = -3/4
<=> k = 12*3/4 = 9