Question

show that the points A -1,1 b 5, 7 and c8, 10 are collinear
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Answer 1

Answer:

plug in the area formula for a triangle and substitute the values for x1,x2,x3,y1,y2,y3 and equate it to zero.

sorry but  i don't have the time to  solve it so am typing the method.

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Step-by-step explanation:

Answer 2

Answer:

To show the points are collinear or not we must find the slopes

Slope of AB = Slope of BC

Step by step explanation:

$ab \: = \frac{7 - 1}{5 + 1}$

$= \frac{6}{6}$

slope of AB = 1

$bc = \frac{10 - 7}{8 - 5}$

$= \frac{3}{3}$

Slope of BC= 1

Hence slop of AB = Slope of BC

since their slopes are equal (1)