Question

the ponits (1,a) , (3,2) , (4a,-1) are collinear find the positive values of a

Answer 1

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Answer 2

Step-by-step explanation:

Mab = Mac= Mbc

Mab= y2-y1/x2-x1

2-a/3-1

2-a/2

Mbc =-1-2/4a-3

Mbc=-3/4a-3

to find a equate the both then cross multiply

2-a/2 = -3/4a-3

(2-a)(4a-3)=-6

expand

2(4a-3)-a(4a-3)=-6

8a+4a2+3a =-6+6

-4a2 +11a=-6+6

-4a2+11a=0

then factorize