Answer:
x = - 6 or x = 2
Explanation:
The absolute value function always returns a positive value. However, the expression inside can be positive or negative.
Given
| 2x + 4 | - 1 = 7 ( add 1 to both sides )
| 2x + 4 | = 8, thus
2x + 4 = 8 ( subtract 4 from both sides )
2x = 4 ( divide both sides by 2 )
x = 2
OR
-(2x + 4) = 8
- 2x - 4 = 8 ( add 4 to both sides )
- 2x = 12 ( divide both sides by - 2 )
x = - 6
As a check
Substitute these values into the left side of the equation and if equal to the right side then they are the solutions.
x = 2 → | 4 + 4 | - 1 = | 8 | - 1 = 8 - 1 = 7 ← True
x = - 6 → | - 12 + 4 | - 1 = | - 8 | - 1 = 8 - 1 = 7 ← True
Hence the solutions are x = - 6 or x = 2