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Question
Show that the following points are collinear:
A(-5,1), B(5, 5) and C(10, 7)
Solution
`"Let " A(x_1=-5,y_1=1), B(x_2=5,y_2=5) and C(x_3= 10,y_3=7)`be the given points.
` Now , x_1(y_2-y_3)+x_2(y_3-y_1)+x_3(y_1-y_2)`
`=(-5)(5-7)+5(7-1)+10(1-5)`
`=-5(-2)+5(6)+10(-4)`
`=10+30-40`
= 0
Hence, the given points are collinear.
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