Question

If the points A(-1,-4)B(b,c) and C(5,-1) are collinear and 2b +c=4,find the value of b and c.

Answer 1

less then 7days

as A-10

B-20

hence in 20day 3work done

hence 1work in 6.67

Answer 2

Answer:

Let A(x1=-1,y1=-4),B(x2=b,y2=c)and C(x3=5,y3=-1) be given points.

Since the points A,B and C are collinear ,we have.

X1(y2-y3)+x2(y3-y1)+x3(y1-y2)=0

-1×(c+1)+b(-1+4)+5(-4-c)=0

-c-1+3b-20-5c=0

3b -6c=21

b-2c=7 ek.(1)

Also it is given that 2b+c =4 ek.(2)

On solving eq.1 and eq.2 ,we get b=3 and c=-2

Hence b=3 and c=-2.