Question

if the points A(x,2),B(-3,-4),C(7,-5) are collinearw find the value of x

Answer 1

$x(4 + 5) - 3( - 5 - 2) + 7(2 + 4) = 0 \\ 9x + 21 + 42 = 0 \\ 9x = - 63 \\ x = - 7$