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The number of distinct real values of x, satisfying the equation.

max {x, 2} - min {x, 2} =∣x+2∣−∣x−2∣= |x + 2| - |x − 2|, is

Entered answer:

Solution

✅ Correct Answer: 2

We need to find how many different real values of xx satisfy this equation:

max⁡{x,2}−min⁡{x,2}=∣x+2∣−∣x−2∣\max\{x, 2\} - \min\{x, 2\} = |x + 2| - |x - 2|

The equation changes behavior at critical points where the expressions inside the max/min and absolute value functions change sign: x=2x = 2 and x=−2x = -2.

This gives us three ranges to check: x≥2x \geq 2, −2<x<2-2 < x < 2, and x<−2x < -2.

Your basic concepts with modulus should be covered to understand this solution. We will find the RHS & LHS for the 3 ranges to find xx and then check if the xx found is valid for the range.


When x≥2x \geq 2:

Left side: Since x≥2x \geq 2, we have xx is at least as large as 22

max⁡{x,2}=x\max\{x, 2\} = x and min⁡{x,2}=2\min\{x, 2\} = 2

So left side = x−2x - 2

Right side: Since x≥2x \geq 2:

x+2≥4x + 2 \geq 4, so ∣x+2∣=x+2|x + 2| = x + 2

x−2≥0x - 2 \geq 0, so ∣x−2∣=x−2|x - 2| = x - 2

Hence, both mod open as positives.

So right side = (x+2)−(x−2)=4(x + 2) - (x - 2) = 4

Our equation becomes: x−2=4x - 2 = 4

Therefore x=6x = 6

Since 6≥26 \geq 2, this solution is valid for this case.


When −2<x<2-2 < x < 2:

Left side: Since x<2x < 2:

max⁡{x,2}=2\max\{x, 2\} = 2 and min⁡{x,2}=x\min\{x, 2\} = x

So left side = 2−x2 - x

Right side: Since −2<x<2-2 < x < 2:

x+2>0x + 2 > 0, so ∣x+2∣=x+2|x + 2| = x + 2

x−2<0x - 2 < 0, so ∣x−2∣=2−x|x - 2| = 2 - x

So right side = (x+2)−(2−x)=2x(x + 2) - (2 - x) = 2x

Our equation becomes: 2−x=2x2 - x = 2x

Therefore 2=3x2 = 3x, so x=23x = \dfrac{2}{3}

Since −2<23<2-2 < \dfrac{2}{3} < 2, this solution is valid for this case.


When x<−2x < -2:

Left side: Since x<−2<2x < -2 < 2:

max⁡{x,2}=2\max\{x, 2\} = 2 and min⁡{x,2}=x\min\{x, 2\} = x

So left side = 2−x2 - x

Right side: Since x<−2x < -2:

x+2<0x + 2 < 0, so ∣x+2∣=−x−2|x + 2| = -x - 2

x−2<0x - 2 < 0, so ∣x−2∣=2−x|x - 2| = 2 - x

So right side = (−x−2)−(2−x)=−4(-x - 2) - (2 - x) = -4

Our equation becomes: 2−x=−42 - x = -4

Therefore x=6x = 6

We need x<−2x < -2 for this case, but we got x=6x = 6. Since 6>−26 > -2, this solution is invalid for this case.


The summary table makes it easier to understand what is happening here:

CaseConditionLeft SideRight SideEquationSolutionValid?
1x ≥ 2x - 24x - 2 = 4x = 6✓
2-2 < x < 22 - x2x2 - x = 2xx = 2/3✓
3x < -22 - x-42 - x = -4x = 6✗

Therefore, the number of distinct real values of xx satisfying the equation is 2.

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