Splitting |x − 5| into two cases invites sign errors in both. The graph shows the whole answer at once: a V you can look at.
The move: Graph the V, then just look.
Why it works: Absolute value is distance from zero, and its graph is a V — where the V sits (touching, crossing, or floating above the axis) IS the answer to solution-count questions.
The pattern
- Type the absolute-value expression
- Graph the V shape
- Tap or count what it asks
Worked example: How many solutions does |x − 3| − 2 = 0 have?
- Type the left side as a graph. That V shape is the absolute value.
y=|x-3|-2 - “= 0” means: where does it cross the x-axis? Tap the curve — two gray dots, at x = 1 and x = 5.
- Two crossings → two solutions. You SAW the answer instead of reasoning about cases.
Worked example 2: What is the sum of the solutions of |2x − 1| = 7?
- Graph both sides.
y=|2x-1|,y=7 - Two crossings: x = −3 and x = 4.
- −3 + 4 = 1. The “±” case-splitting happened visually.
Remember it on test day
Graph the V, just look. That's the whole cue — say it when you see this question type and the steps follow.
When this isn't the move
Pure definition questions (“|−7| = ?”) are faster in your head than in any calculator.
Drill it until it's reflex
This move is one of Desvantage's 18 training modules: a plain-English lesson, a type-it-yourself walkthrough inside a live Desmos calculator, and a 100-question drill bank that deals ten fresh questions per round. The first two modules — plus the 12-question diagnostic — are free.
