Chapter 3.5, Problem 43E

To determine

To graph: The solution of the inequality $-3.9c\le 43.68$ using calculator.

Explanation of Solution

Given information:

  $-3.9c\le 43.68$

Graph:

Use graphing calculator to graph the inequality:

Step 1: Press $\boxed{\text{Y=}}$ button on the calculator.

Step 2: Enter the inequality equation (define the inequality)

Step 3: Set the windows according to the graph.

Step 4: Press $\boxed{\text{Graph}}$ button to obtain the graph of the inequality.

Hence,

The graph thus obtained is shown below:

  

  $c\ge -11.2$ is shown in the graph.

Interpretation:

  $\begin{array}{l}-3.9c\le 43.68\text{ original inequality}\\ \frac{-3.9c}{-3.9}\ge \frac{43.68}{-3.9}\text{ divide each side by -3}\text{.9 }\\ \text{ reverse the inequality}\\ c\ge -11.2\text{ simplify}\end{array}$

From, the above graph, it is observed that the solution of the inequality is all number greater and equal to $-11.2$

Hence, $c\ge -11.2$