Chapter 4.1, Problem 31PPS

To determine

To graph: Sketch the graph of the equation $21=7y$ .

Explanation of Solution

Given information: The given equation of the line is written as $21=7y$ , which after simplification can be written as

  $\begin{array}{c}7y=21\\ \text{or, }y=3\end{array}$

Graph: Now $y=3$ is an equation of the form $y=k$ where $k$ is any constant. Also an equation of the form $y=k$ is a horizontal straight line parallel to $x-axis$ at a distance $k$ units from $x-axis$ . Therefore, the graph of the straight line $y=3$ is a horizontal straight line parallel to $x-axis$ at a distance $3$ units from $x-axis$ as shown

  

Interpretation: The obtained graph is a horizontal straight line parallel to $x-axis$ at a distance $3$ units from $x-axis$ .