If the three distinct lines
` x + 2ay + a = 0 , x+ 3by + b = 0` and
`x + 4ay + a = 0 ` are concurrent , then the point (a,b) lies on a .

For a ne b ne c if the lines x + 2ay + a = 0 , x + 3by + b = 0 and x + 4cy + c = 0 ar concurrent , then a , b, c are in

If the lines ax + by + c = 0, bx + cy + a = 0 and cx + ay + b = 0 be concurrent, then:

if the lines x + 2ay + a = 0, x + 3by + b = 0 and x + 4cy + c = 0 are concurrent, then a, b, c are in: (1) A.P.(2) G.P.(3) H.P.(4) A.G.P.

If the lines x +3y -9 = 0, 4x + by -2 = 0 and 2x -y -4 = 0 are concurrent , the b is equal to

If the lines (a-b-c) x + 2ay + 2a = 0 , 2bx + ( b- c - a) y + 2b = 0 and (2c+1) x + 2cy + c - a - b = 0 are concurrent , then the prove that either a+b+ c = 0 or (a+b+c)^(2) + 2a = 0

If the lines (a-b-c) x + 2ay + 2a = 0 , 2bx + ( b- c - a) y + 2b = 0 and (2c+1) x + 2cy + c - a - b = 0 are concurrent , then the prove that either a+b+ c = 0 or (a+b+c)^(2) + 2a = 0

If a system of three linear equations x + 4ay + a = 0, x + 3by + b = 0, and x + 2cy + c = 0 is consistent, then prove that a,b,c are in H.P.

If the lines (a-b-c) x + 2ay + 2a = 0 , 2bx + ( b- c - a) y + 2b = 0 and (2c+1) x + 2cy + c - a - b = 0 are concurrent , then prove that either a+b+ c = 0 or (a+b+c)^(2) + 2a = 0

If the straight lines a x + m ay + 1 =0 b x + ( m +1) by + 1 =0 cx + (m+2) cy +1 =0, m ne0 are concurrent, then a, b, c are in :