Interpret absolute value as distance and use it to compare quantities and errors.
Work backward from an absolute value condition
Problem
Find \(\text{all}~\text{signed}~\text{values}\) of \(x\) that make \(|x|~=~4\).
Big Picture
What this problem is really about
Read the equation as a distance condition: x must be exactly four units from zero. Distance does not specify direction, so move four units from zero on both sides of the number line and record both signed locations. Substitute each one into the absolute-value equation to verify that the full solution set is complete.
Inside Gozunta
Turn the preview into practice.
More than a preview
Gozunta lets you study this problem—and more than 10,000 others.
Create targeted learning sessions, use hints, check your answer, read the walkthrough, watch the video, print the work, and track your progress.