Menu

Distance from a Point

Part of the Inequalities & Absolute Value section of Coddy's Algebra journey. Lesson 40 of 61.

The equation ∣x−2∣=5\left|x-2\right| = 5 asks which numbers are five steps from 2. Split it into two cases, x−2=5x-2 = 5 or x−2=−5x-2 = -5, then add 2 to both sides in each case:

x=7x = 7

or

x=−3x = -3

-3 and 7 are both five steps from 2

-3 and 7 are both five steps from 2

The expression ∣x−a∣\left|x-a\right| is the distance between xx and aa. So ∣x−2∣=5\left|x-2\right| = 5 says the distance between xx and 2 is 5, and the two solutions are the two numbers five steps from 2. The algebra gives the same answer: split, solve each case, and the two answers are the same distance from 2, one on each side.

challenge icon

Challenge

Medium

Solve the equation ∣x−1∣=4\left|x-1\right| = 4 for xx.

Try it yourself

∣x−1∣=4\left|x-1\right| = 4

Get xx alone

All lessons in Inequalities & Absolute Value