Answer:
x = -63
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!