Solve |x − 2| = 4
Absolute value equation, worked out line by line the way a teacher would write it.
Answer
| Solutions | x = −2, x = 6 |
Step-by-step solution
7 steps-
1 Given\left|{x - 2}\right| = 4
Solve for x.
-
2 Split into two cases: the expression inside the bars is either 4 or -4
|u| is the distance of u from 0. A distance of 4 can be on either side of 0, so the inside is 4 or the opposite of 4, and each case is solved as its own equation.
x - 2 = 4\quad \text{or} \quad x - 2 = -4 -
3 Case 1x - 2 = 4
-
4 Add 2 to both sides
An equation stays true as long as you do the same thing to both sides, like adding the same weight to both pans of a balance. Adding or subtracting the same amount on both sides moves a term to the other side, where it appears with the opposite sign.
x = 6Move the constant terms to the right.
-
5 Case 2x - 2 = -4
-
6 Add 2 to both sidesx = -2
Move the constant terms to the right.
-
7 Check\begin{aligned}x = -2:\quad 4 = 4\quad\checkmark\\ x = 6:\quad 4 = 4\quad\checkmark\end{aligned}
Substituting each solution back makes both sides equal.
Check by substitution
| x | Left side | Right side | |
|---|---|---|---|
| −2 | 4 | 4 | ✓ |
| 6 | 4 | 4 | ✓ |
Open this problem in the solver
Change a number or try your own problem: the solver works it out the same way, with a graph and hint mode.