Respuesta :

Simple....

using the formula [tex] \frac{ y_{1}- y_{2} }{ x_{1}- x_{2} } [/tex] to find slope....

1.)  (9,2)(4,3)

[tex] \frac{2-3}{9-4}= -\frac{1}{5} [/tex] (No)

2.)  (9,2)(3,4)

[tex] \frac{2-4}{9-3} = -\frac{2}{6} =- \frac{1}{3} [/tex] (No)

3.)  (2,9)(3,4)

[tex] \frac{9-4}{2-3} = \frac{5}{-1} =-5[/tex] (No)

4.)  (2,9)(4,3)

[tex] \frac{9-3}{2-4} = \frac{6}{-2} =-3[/tex] (YES!)

Thus, your answer.