If x,y and z are in AP, then x, y−1 and z are in?
Option (c) Take y=2 and x+y1−xy = 1 and (y+z)1−yz= 3
When y=2. x=−13 and z = 17,
2(−13)(17)(17)−(13)=12=y−1... hence they are in HP
if the lines ax+2y+1=0, bx+3y+1=0, cx+4y+1=0 are concurrent then a,b,c are in:
a) AP
b)GP
c)HP
d)Neither GP or AP