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Question
Show that the following points are collinear:
A(8,1), B(3, -4) and C(2, -5)
Solution
`"Let" A(x_1=8,y_1=1), B (x_2=3, y_2=-4) and C (x_3 = 2, y_3=-5) ` be the given points.
Now `x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2)`
=8 (-4+5) +3 (-5-1) +2(1+4)
= 8 - 18 + 10
=0
Hence, the given points are collinear.
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