Question:
Find the slope of a line which passes through the points
(i) $(0,0)$ and $(4,-2)$
(ii) $(0,-3)$ and $(2,1)$
(iii) $(2,5)$ and $(-4,-4)$
(iv) $(-2,3)$ and $(4,-6)$
Solution:
If a line passing through $\left(x_{1}, y_{1}\right) \&\left(x_{2}, y_{2}\right)$ then slope of the line is given
by slope $=\left(\frac{y_{2}-y_{1}}{x_{2}-x_{1}}\right)$
(i) Given points are $(0,0)$ and $(4,-2)$
slope $=\left(\frac{-2-0}{4-0}\right)$
$=\frac{-1}{2}$
(ii) Given points are $(0,-3)$ and $(2,1)$
slope $=\left(\frac{1-(-3)}{2-0}\right)$
$=2$
(iii) Given points are $(2,5)$ and $(-4,-4)$
slope $=\left(\frac{-4-5}{-4-2}\right)$
$=\frac{3}{2}$
$=1.5$
(iv) Given points are $(-2,3)$ and $(4,-6)$
slope $=\left(\frac{-6-3}{4+2}\right)$
$=\frac{-3}{2}$
$=-1.5$