How do you find the slope given (7,9) and (1,1)?

May 27, 2017

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:

$m = \frac{\textcolor{red}{1} - \textcolor{b l u e}{9}}{\textcolor{red}{1} - \textcolor{b l u e}{7}} = \frac{- 8}{-} 6 = \frac{- 2 \times 4}{- 2 \times 3} = \frac{\textcolor{red}{\cancel{\textcolor{b l a c k}{- 2}}} \times 4}{\textcolor{red}{\cancel{\textcolor{b l a c k}{- 2}}} \times 3} = \frac{4}{3}$