What are the solution(s) to the following equation? Select each correct answer.



$|2x - 5| = 11$


  • no solution
  • $x = 8$
  • $x = 3$
  • $x = -3$
  • $x = 6$
  • $x = -8$
  • all real numbers

Verified Answer :

  • To solve the equation \(|2x - 5| = 11\), split it into two cases: \(2x - 5 = 11\) and \(2x - 5 = -11\).
  • Solving the first case, \(2x = 16\), results in \(x = 8\).
  • Solving the second case, \(2x = -6\), results in \(x = -3\).
  • The correct solutions are \(\boxed{x = 8, x = -3}\).

Explanation

  1. Understanding Absolute Value Equations

The equation provided is \(|2x - 5| = 11\). The absolute value function \(|u|\) measures the distance of \(u\) from zero. An equation of the form \(|u| = a\) (where \(a > 0\)) means that the expression \(u\) is at a distance of \(a\) from zero, which implies that \(u\) must be equal to \(a\) or \(u\) must be equal to \(-a\). In our case, \(u = 2x - 5\) and \(a = 11\), so we need to solve for two separate cases.

  1. Solving the Linear Equations

Based on the property of absolute values, we split the equation \(|2x - 5| = 11\) into two distinct linear equations:

  1. \(2x - 5 = 11\)
  2. \(2x - 5 = -11\)

We solve each case individually.
Case 1:
\(2x - 5 = 11\)
Adding 5 to both sides:
\(2x = 16\)
Dividing by 2:
\(x = 8\)

Case 2:
\(2x - 5 = -11\)
Adding 5 to both sides:
\(2x = -6\)
Dividing by 2:
\(x = -3\)

  1. Selecting the Correct Answers

The solutions to the equation \(|2x - 5| = 11\) are \(x = 8\) and \(x = -3\). Comparing these results with the provided options, we select:

  • \(x = 8\)
  • \(x = -3\)

Examples

Absolute value equations are essential in many practical scenarios where you are interested in the difference from a target value regardless of the direction. For instance, if a manufacturing machine is supposed to cut metal rods to a target length of 5 cm, but has a tolerance of 11 cm, you would express the range of acceptable variations as \(|L - 5| \le 11\), where \(L\) is the actual length. Solving such equations helps technicians define the boundaries of acceptable quality control in production environments.