Question

If (a,0),(0,b) and (3,2) are collinear,show that 2a+3b-ab=0.

Answer 1

three points colinear means triangle form by three points is zero
i.e.A (a,0) B (0, b) and C(3,2)
ar (ABC)=1/2{a(b-2)+0+3(0-b)}
0 =ab-2a-3b
hence
2a+3b-ab=0

Answer 2

When three points are collinear it means the area of triangle is equal to 0
So area of triangle -->
=> 1/2 [ a ( b - 2) + 0 ( 3 - 0) + 3 ( 0 - b)] = 0
=> ab - 2a - 3b = 0
=> - 2a - 3b + ab = 0
=> - ( - 2a - 3b + ab) = 0
=> 2a + 3b - ab = 0