Question

What is the slope of the line through (-9,6) and (-6,-9)

Answer 1

$\text{The slope formula:}\ m=\dfrac{y_2-y_1}{x_2-x_1}\\\\\text{We have:}\\(-9;\ 6)\to x_1=-9;\ y_1=6\\(-6;\ -9)\to x_2=-6;\ y_2=-9\\\\\text{substitute:}\\\\m=\dfrac{-9-6}{-6-(-9)}=\dfrac{-15}{-6+9}=\dfrac{-15}{3}=-5$

Answer: m = -5