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# How do you find the slope given (9,6) (21,14)?

Mar 9, 2018

See a solution process below:

#### Explanation:

The slope can be found by using the formula: $m = \frac{\textcolor{red}{{y}_{2}} - \textcolor{b l u e}{{y}_{1}}}{\textcolor{red}{{x}_{2}} - \textcolor{b l u e}{{x}_{1}}}$

Where $m$ is the slope and ($\textcolor{b l u e}{{x}_{1} , {y}_{1}}$) and ($\textcolor{red}{{x}_{2} , {y}_{2}}$) are the two points on the line.

Substituting the values from the points in the problem gives:

$m = \frac{\textcolor{red}{14} - \textcolor{b l u e}{6}}{\textcolor{red}{21} - \textcolor{b l u e}{9}} = \frac{8}{12} = \frac{4 \times 2}{4 \times 3} = \frac{\textcolor{red}{\cancel{\textcolor{b l a c k}{4}}} \times 2}{\textcolor{red}{\cancel{\textcolor{b l a c k}{4}}} \times 3} = \frac{2}{3}$