Answer:
x = 3
Step-by-step explanation:
[tex]m = \frac{y \frac{}{2} - y \frac{}{1} }{x \frac{}{2} - x \frac{}{1} } [/tex]
m = slope
x, y = coordinates
[tex] - 4 = \frac{1 - ( - 3)}{x - 4} \\ - 4(x - 4) = 1 + 3 \\ - 4x + 16 = 4 \\ - 4 x = 4 - 16 \\ - 4x = - 12 \\ x= \frac{ - 12}{ - 4} \\ x = 3[/tex]