Question

25. Find the value of m for which the points (1.2),(5, 1) and (3, m) are collinear.
10
11
of tuin nimilar triangles are 30 cm and 20 cm respectively. If one side of the​

Answer 1

Answer:

the answer is :3/2

Step-by-step explanation:

if collinear then area should be 0

∴ area of the points (1,2),(5,1),(3,m) =0

we know that: area formula = 1/2[x1(y2-y3)+x2(y3-y1)+x3(y1-y2)]=Δ

∴(1,2)=(x1,y1) ,  (5,1)=(x2,y2) ,  (3,m)=(x3,y3)

Δ=1/2[1(1-m)+5(m-2)+3(2-1)=0  {as they are collinear}

1/2[1-m+5m-10+3(1)]=0

1/2[1+4m-10+3]=0

1/2[4m-6]=0      {send 1/2 to the right side}

[4m/2-6/2]=0

[2m-3]=0

2m=3

m=3/2