Question

If the points A(x,2), B(-3, -4) and C(7, -5) are collinear, then find the value of x

Answer 1

Answer:

x = -63

Step-by-step explanation:

If the points A(x,2), B(-3, -4), and C(7, -5) are collinear, the line that passes B and C, also passes A.

The line passes B and C has the form of y = ax + b

=> -4  = a(-3) + b

    -5  = a(7) + b

=> Subtraction 1st equation from 2nd equation, we have:

    -1 = 10a

=> a = -1/10

=> b = -4 + 3(-1/0) = -43/10

=> This line has form of y = (-1/10)x -43/10

This line passes A(x, 2)

=> 2 = (-1/10)x - 43/10

=> 2 + 43/10 = (-1/10)x

=> 63/10 = (-1/10)x

=> x = -63

Hope this helps!