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15 votes
15 votes
Find the distance between the parallel line y = 2x + 7 y = 2x - 2

User Kim Burgaard
by
2.6k points

1 Answer

21 votes
21 votes

A line is represented by the following expression:


\begin{gathered} y=mx+b \\ \text{where,} \\ m=\text{slope} \\ b=y-\text{intercept} \end{gathered}

Since they are parallel because they have the same slope, we can find the distance between them with the formula for distance between points:


\begin{gathered} y=2x+7 \\ y=2(1)+7 \\ y=9 \\ \text{Point for the first line (1,9)} \\ \\ y=2x-2 \\ y=2(1)-2 \\ y=0 \\ \text{Point for the second line (1,0)} \end{gathered}

Distance between points is represented by the following expression:


d=\sqrt[]{(x_2-x_1)^2+(y_2-y_1)}^2
\begin{gathered} d=\sqrt[]{(1-1)^2+(9-0)^2} \\ d=\sqrt[]{9^2} \\ d=9\text{ units} \end{gathered}

The distance between the lines is 9 units.

User ItayMiz
by
2.7k points
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