Question

If A(2,1) ,B(5,4) and C (7,c) are collinear points find the possible value of c . 
​

Answer 1

Step-by-step explanation:

Given points are A(x,2)B(−3,−4)C(7,−5)

(x

1

,y

1

)=(x,2),(x

2

,y

2

)=(−3,−4)(x

3

,y

3

)=(7,−5)

x

1

[y

2

−y

3

]+x

2

[y

3

−y

1

]+x

3

[y

1

−y

2

]=0

x[(−4)−(−5)]+(−3)[(−5)−2]+7[2−(−4)]=0

x(−4+5)−3(−5−2)+7(2+4)=0

x(1)−3(−7)+7(6)=0

x+21+42=0

x+63=0

x=−63

∴ The value of x is −63.