Determine which integer will make the inequality $12>2 x+4$ true.


A$S:\{8\}$
B$S:\{4\}$
C$S:\{12\}$
D$S:\{-2\}$

Verified Answer :

  • Simplify the inequality \(12 > 2x + 4\) to \(x < 4\) by subtracting 4 and dividing by 2.
  • Test the given options: \(8\), \(4\), \(12\), and \(-2\) against the condition \(x < 4\).
  • Identify that only \(-2\) satisfies the inequality, which corresponds to the set \(S = \{-2\}\).
  • Final Answer: \(\boxed{S = \{-2\}}\)

Explanation

  1. Understanding the Inequality

We are tasked with solving the inequality \(12 > 2x + 4\) for \(x\) and determining which of the provided sets contains the integer that satisfies this condition. The set options are \(S = \{8\}\), \(S = \{4\}\), \(S = \{12\}\), and \(S = \{-2\}\). To solve the inequality, we need to isolate the variable \(x\).

  1. Solving the Inequality

To isolate \(x\), we first subtract 4 from both sides of the inequality:
\[12 - 4 > 2x\]
\[8 > 2x\]
Next, divide both sides by 2:
\[\frac{8}{2} > \frac{2x}{2}\]
\[4 > x\]
This means the inequality \(12 > 2x + 4\) is equivalent to \(x < 4\). Any integer \(x\) that is strictly less than 4 will satisfy the original inequality.

  1. Testing the Candidate Values

Now, we test each candidate set to see which one satisfies \(x < 4\):

  • For \(S = \{8\}\): \(8 < 4\) is False.
  • For \(S = \{4\}\): \(4 < 4\) is False.
  • For \(S = \{12\}\): \(12 < 4\) is False.
  • For \(S = \{-2\}\): \(-2 < 4\) is True.

Thus, the only set containing an integer that makes the inequality true is \(S = \{-2\}\).

Examples

Understanding inequalities is fundamental in budgeting. For example, if you have a budget of \(\$12\) and you need to pay a fixed fee of \(\$4\), the remaining amount you can spend is represented by the inequality \(12 > 2x + 4\), where \(2x\) is the cost of items you want to buy. By solving \(x < 4\), you quickly determine that you can afford at most 3 items, as buying 4 items would cost exactly \(\$12\), reaching your limit. This application helps in making informed financial decisions daily.