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Question

If $|4X - 7| = 5$ then the values of $2 |X| – | – X|$ is:

The correct answer is
1/2, 3

Solving the Absolute Value Equation $|4X - 7| = 5$

The problem asks for the values of the expression $2 |X| – | – X|$ given the equation $|4X - 7| = 5$. First, we need to solve the absolute value equation for $X$.

  1. Split the equation: An absolute value equation $|A| = B$ implies $A = B$ or $A = -B$. So, $|4X - 7| = 5$ means:

    • Case 1: $4X - 7 = 5$
    • Case 2: $4X - 7 = -5$
  2. Solve Case 1:

    $4X - 7 = 5$

    Add 7 to both sides:

    $4X = 5 + 7$

    $4X = 12$

    Divide by 4:

    $X = \frac{12}{4}$

    $X = 3$

  3. Solve Case 2:

    $4X - 7 = -5$

    Add 7 to both sides:

    $4X = -5 + 7$

    $4X = 2$

    Divide by 4:

    $X = \frac{2}{4}$

    $X = \frac{1}{2}$

    So, the possible values for $X$ are $3$ and $\frac{1}{2}$.

  4. Simplify the expression: The expression to evaluate is $2 |X| – | – X|$. Recall the property of absolute values: $|-a| = |a|$. Applying this, we get:

    $2 |X| – | – X| = 2 |X| - |X| = |X|$

    The expression simplifies to just $|X|$.

  5. Evaluate the simplified expression for each value of X:

    • If $X = 3$, then $|X| = |3| = 3$.
    • If $X = \frac{1}{2}$, then $|X| = |\frac{1}{2}| = \frac{1}{2}$.

    Therefore, the possible values for the expression $2 |X| – | – X|$ are $3$ and $\frac{1}{2}$.

Comparing this result with the options, Option B contains the values $\frac{1}{2}$ and $3$.

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Important Questions from Absolute Value Function

  1. Which one of the following plots represents $f(x) = -\frac{|x|}{x}$, where x is a non-zero real number?
    Note: The figures shown are representative.
  2. Which one of the given figures P, Q, R and S represents the graph of the following function? 
    $f(x) = | |x + 2| - |x - 1| |$

  3. Which of the following functions describe the graph shown in the below figure?

  4. If $|9y-6|=3$, then $y^2 -4y/3$ is ________
  5. If $|-2X + 9| = 3$ then the possible value of $|-X| – X^2$ would be:
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