Forms of linear equations: summary

Finally, review how to get information about the line using any form of a linear equation representing this line.

Linear equations in any form - Questions

Answers

1. y+2=\frac{4}{5}(x-2).

The line passes through (-3,-6) and (2,-2).

We don't have the y-intercept so it's most comfortable to write an equation in point-slope form.

\begin{aligned}
\text { Slope } &=\frac{(-2)-(-6)}{2-(-3)} \\
&=\frac{4}{5}
\end{aligned}

Using the point (2,-2), an equation that represents the line is y+2=\frac{4}{5}(x-2).


2. y=\frac{3}{2} x+3.

The line passes through (0,3) and (2,6).

We have the y-intercept so it's most comfortable to find the slope-intercept form of the line.

\begin{aligned}
\text { Slope } &=\frac{6-3}{2-0} \\
&=\frac{3}{2}
\end{aligned}

An equation that represents the line is y=\frac{3}{2} x+3.


3. y-4=\frac{7}{5}(x+2).

The line passes through (-7,-3) and (-2,4).

We don't have the y-intercept so it's most comfortable to write an equation in point-slope form.

\begin{aligned}
\text { Slope } &=\frac{4-(-3)}{(-2)-(-7)} \\
&=\frac{7}{5}
\end{aligned}

Using the point (-2,4), an equation that represents the line is y-4=\frac{7}{5}(x+2).


4.  y=\frac{6}{5} x-5

The line passes through (0,-5) and (5,1).

We have the y-intercept so it's most comfortable to find the slope-intercept form of the line.

\begin{aligned}
\text { Slope } &=\frac{1-(-5)}{5-0} \\
&=\frac{6}{5}
\end{aligned}

An equation that represents the line is y=\frac{6}{5} x-5.