Verified Answer :

  • Simplify the expression by expanding both sides: \(3n - 18 < 2n + 24\).
  • Isolate the variable \(n\) to find the range: \(n < 42\).
  • Determine that the inequality is false for values \(n \geq 42\).
  • Identify that the option \(42\) satisfies this condition, making the final answer \(\boxed{42}\).

Explanation

  1. Analyzing the Inequality

The given inequality is \(3(n - 6) < 2(n + 12)\). We want to determine which of the provided integers \(n\) makes this inequality false. The original inequality is true if the left-hand side is strictly less than the right-hand side. It is false if the left-hand side is greater than or equal to the right-hand side. We will simplify the expression first to find the range of values for which the inequality holds.

  1. Solving the Inequality for n

We expand the expression on both sides of the inequality:
Left-hand side (LHS): \(3(n - 6) = 3n - 18\)
Right-hand side (RHS): \(2(n + 12) = 2n + 24\)
The inequality becomes:
\(3n - 18 < 2n + 24\)
To solve for \(n\), we subtract \(2n\) from both sides:
\(n - 18 < 24\)
Then, we add \(18\) to both sides:
\(n < 42\)
This means the inequality holds true for all values of \(n\) strictly less than \(42\). Conversely, the inequality is false if \(n \geq 42\).

  1. Testing the Options

We evaluate the provided options: \(\{-5\}, \{3\}, \{12\}, \{42\}\).

  • For \(n = -5\): \(-5 < 42\) is true.
  • For \(n = 3\): \(3 < 42\) is true.
  • For \(n = 12\): \(12 < 42\) is true.
  • For \(n = 42\): \(42 < 42\) is false, since \(42\) is not strictly less than \(42\).

Therefore, the integer that makes the inequality false is \(42\).

Examples

In real-world scenarios, inequalities help define boundaries, such as in production planning where a factory must ensure their production rate, say \(n\), does not exceed a certain capacity. For example, if you are planning to produce items at a rate \(n\) per hour, and your equipment efficiency follows the rule \(3(n - 6) < 2(n + 12)\), you need to find the limit of your production rate before the system becomes inefficient or false. Solving for \(n < 42\) tells you that the system works efficiently for any rate below 42 items per hour, and you'll know exactly at what point you need to stop or recalibrate.