Answer:
Step-by-step explanation:
Given two points on the line:
Use the slope equation:
Slope:-
[tex]\sf\longmapsto m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
[tex]\sf\longmapsto m=\dfrac{-4-78}{90-86}[/tex]
[tex]\sf\longmapsto m=\dfrac{-82}{4}[/tex]
[tex]\sf\longmapsto m=-41/2[/tex]
[tex]\sf\longmapsto m=20.5[/tex]