Question

find the value of p for which the points (-1,3),(2,p)and (5,-1) are collinear
please help me urgently

Answer 1

Answer :

Since the given points are collinear, the slope of the line joining the points (-1, 3) and (2, p) is equal to the slope of the line joining the points (-1, 3) and (5, - 1).

Thus,

$\frac{p-3}{2-(-1)}=\frac{-1-3}{5-(-1)}$

$\implies \frac{p-3}{2+1} = \frac{-4}{5+1}$

$\implies \frac{p-3}{3}=\frac{-4}{6}$

$\implies$ 6 (p - 3) = 3 (- 4)

$\implies$ 6p - 18 = - 12

$\implies$ 6p = - 12 + 18 = 6

Therefore, p = 1

#MarkAsBrainliest

Answer 2

Answer:

For collinearity of points A(−1,3),B(2,p),C(5,−1), area of ΔABC should be zero ,i.,e,

2

1

∣(p−1)+2(−1−3)+5(3−p)∣=0

⇒p−1−8+15−5p=0

⇒−6p+6=0

⇒−6p=−6

⇒p=1