Q28 of 49 Page 1

Find the value of x for which the points (x, 1), (2, 1) and (4, 5) are collinear.

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If the three points are collinear then the area of the triangle formed by them will be zero.


∴ Area of given Δ ABC = 0


⇒ (1/2)|x(1-5)+2(5-1)+4(1-1)| =0


⇒ x(-4)+2(4)+4(0) = 0


⇒ -4x+8 = 0


∴ x = 2


Thus, the value of x is 2.


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