Question

For what value of K the pair of equations 3x+4y+2=0 and 9x+12y+k represent coincident lines

Answer 1

hope u got it
see attachment

Answer 2

if we take x=2
y=-2
9x+12+k=0
9X2+12X-2+k=0
18+(-24)+k=0
-6+k=0
k=6