Question -
Answer -
If given points are collinear then area oftriangle formed by them must be zero.
Let (x, y), (1, 2) and (7, 0) are vertices ofa triangle,
Area of a triangle = = 0
[x(2 тАУ 0) + 1 (0 тАУ y) + 7( yтАУ 2)] = 0
- 2x тАУ y + 7y тАУ 14 = 0
- 2x + 6y тАУ 14 = 0
- x + 3y тАУ 7 = 0. Which is required result.