Paul's Online Notes
Paul's Online Notes
Home / Algebra / Solving Equations and Inequalities / Absolute Value Inequalities
Show Mobile Notice Show All Notes Hide All Notes
Mobile Notice
You appear to be on a device with a "narrow" screen width (i.e. you are probably on a mobile phone). Due to the nature of the mathematics on this site it is best viewed in landscape mode. If your device is not in landscape mode many of the equations will run off the side of your device (you should be able to scroll/swipe to see them) and some of the menu items will be cut off due to the narrow screen width.

Section 2.15 : Absolute Value Inequalities

2. Solve the following equation.

\[\left| {6 - 5x} \right| \le 10\]

Show All Steps Hide All Steps

Start Solution

There really isn’t all that much to this problem. All we need to do is use the formula for “less than” inequalities we discussed in the notes for this section. Doing that gives,

\[ - 10 \le 6 - 5x \le 10\] Show Step 2

To get the solution all we need to do then is solve the double inequality from the previous step. Here is that work.

\[\begin{array}{c} - 10 \le 6 - 5x \le 10\\ - 16 \le - 5x \le 4\\ \displaystyle \require{bbox} \bbox[2pt,border:1px solid black]{{\frac{{16}}{5} \ge x \ge - \frac{4}{5}}}\end{array}\]

Remember that when dividing all parts of an inequality by a negative number (as we did here) we need to also switch the direction of the inequalities!