Prove that the points `(a ,\ b),\ (a_1,\ b_1)` and `(a-a_1,\ b-b_1)` are collinear if `a b_1=a_1b` .

Prove that the points (a ,\ 0),\ (0,\ b) and (1,\ 1) are collinear if, 1/a+1/b=1 .

Prove that the points (a ,\ 0),\ (0,\ b) and (1,\ 1) are collinear if, 1/a+1/b=1 .

If the points (a_1, b_1),\ \ (a_2, b_2) and (a_1+a_2,\ b_1+b_2) are collinear, show that a_1b_2=a_2b_1 .

Show that the points (a, 0), (0, b) and (1, 1) are collinear if 1/a + 1/b = 1

If points (a ,\ 0),\ (0,\ b) and (1,\ 1) are collinear, then 1/a+1/b= (a) 1 (b) 2 (c) 0 (d) -1

If the lines a_1x+b_1y+1=0,\ a_2x+b_2y+1=0\ a n d\ a_3x+b_3y+1=0 are concurrent, show that the points (a_1, b_1),\ (a_2, b_2)a n d\ (a_3, b_3) are collinear.

If the lines a_1x+b_1y+1=0,\ a_2x+b_2y+1=0\ a n d\ a_3x+b_3y+1=0 are concurrent, show that the points (a_1, b_1),\ (a_2, b_2)a n d\ (a_3, b_3) are collinear.

If the lines a_1x+b_1y+1=0,a_2x+b_2y+1=0 and a_3x+b_3y+1=0 are concurrent, show that the point (a_1, b_1),(a_1, b_2) and (a_3, b_3) are collinear.

If the points (a,b),(1,1)and (2,2) are collinear then

If the points (a_(1),b_(1))m(a_(2),b_(2))" and " (a_(1)-a_(2),b_(2)-b_(2)) are collinear, then prove that a_(1)/a_(2)=b_(1)/b_(2)