find the slope of the line that passes through each pair of points
Use the slope formula: [tex] \frac{y2-y1}{x2-x1} [/tex]
1. (4, 9), (1, -6)
[tex] \frac{-6-9}{1-4} = \frac{-15}{-3} = 5 [/tex]
2. (2, 5), (6, 2)
[tex] \frac{2-5}{6-2} = \frac{-3}{4} [/tex]
3. (4, 3.5), (-4, 3.5)
[tex] \frac{3.5-3.5}{-4-4} = \frac{0}{-8} =0 [/tex]
4. (1, -2), (-2, -5)
[tex] \frac{-5-(-2)}{-2-1} =\frac{-3}{-3} = 1 [/tex]