Solve ||1-4|+3|-|a|<0: Complex Absolute Value Inequality

Question

Given:

||1-4|+3|-|a|<0

Which of the following statements is necessarily true?

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Simplify the expression inside the absolute values.
  • Step 2: Analyze the inequality and interpret the result.
  • Step 3: Determine which condition on a a satisfies the inequality.

Now, let's work through each step:

Step 1: Simplify the expression inside the absolute values.
Inside the first absolute value, calculate 14 |1-4| . We have 14=3 1-4 = -3 , so 3=3 |-3| = 3 .
Now, calculate 3+3=6=6 |3+3| = |6| = 6 .
Thus, the expression becomes |6 - |a|| < 0 .

Step 2: Analyze the inequality.
The absolute value of any real number is non-negative, meaning 6a0 |6 - |a|| \geq 0 .
The inequality |6 - |a|| < 0 suggests that it's impossible to have a non-negative number less than 0 unless it results in exactly zero, which isn’t possible here.
However, for this particular structure, note if 6a0 6 - |a| \neq 0 , the inequality comes from where an incorrect assumption in formulation.

Step 3: Solving the inequality.
For 6 - |a| < 0 , we solve for a a :
6 < |a|

This inequality a>6 |a| > 6 means:

  • a>6 a > 6
  • or a<6 a < -6

Therefore, the solution to the problem is that a a must satisfy a>6 a > 6 or a<6 a < -6 .

Therefore, the correct choice is: a>6 a > 6 or a<6 a < -6 .

Answer

a > 6 or a < -6