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Question

Quantitative Aptitude Question on Algebra

The number of distinct real values of x, satisfying the equation max{x, 2} - min{x, 2} = |x + 2| - |x - 2|, is

Answer

We are given the equation maxx,2minx,2=x+2x2\max\\{x, 2\\} - \min\\{x, 2\\} = |x+2| - |x-2|, and we need to find the number of distinct real solutions.
Let's analyze both sides of the equation:
The expression maxx,2minx,2\max\\{x, 2\\} - \min\\{x, 2\\} represents the absolute difference between xx and 2, i.e., x2|x - 2|.
The right-hand side of the equation x+2x2|x + 2| - |x - 2| is more complicated; so we need to analyze it case by case based on the value of xx.

Case 1 : x>2x > 2. In this case: maxx,2=x\max\\{x, 2\\} = x, minx,2=2\min\\{x, 2\\} = 2. So the left-hand side becomes x2x - 2.
On the right-hand side: x+2=x+2|x + 2| = x + 2, x2=x2|x - 2| = x - 2. So the right-hand side becomes (x+2)(x2)=4(x + 2) - (x - 2) = 4.
Equating both sides:
x2=4    x=6x - 2 = 4 \implies x = 6
Thus, x=6x = 6 is a solution for x>2x > 2.

Case 2 : x<2x < 2. In this case: maxx,2=2\max\\{x, 2\\} = 2, minx,2=x\min\\{x, 2\\} = x. So the left-hand side becomes 2x2 - x.
On the right-hand side: x+2=x+2|x + 2| = x + 2, x2=2x|x - 2| = 2 - x. So the right-hand side becomes (x+2)(2x)=2x(x + 2) - (2 - x) = 2x.
Equating both sides:
2x=2x    2=3x    x=232 - x = 2x \implies 2 = 3x \implies x = \frac{2}{3}
Thus, x=23x = \frac{2}{3} is a solution for x<2x < 2.

Conclusion: The solutions are x=6x = 6 and x=23x = \frac{2}{3}, so the number of distinct real solutions is 2.

Explanation

Solution

We are given the equation maxx,2minx,2=x+2x2\max\\{x, 2\\} - \min\\{x, 2\\} = |x+2| - |x-2|, and we need to find the number of distinct real solutions.
Let's analyze both sides of the equation:
The expression maxx,2minx,2\max\\{x, 2\\} - \min\\{x, 2\\} represents the absolute difference between xx and 2, i.e., x2|x - 2|.
The right-hand side of the equation x+2x2|x + 2| - |x - 2| is more complicated; so we need to analyze it case by case based on the value of xx.

Case 1 : x>2x > 2. In this case: maxx,2=x\max\\{x, 2\\} = x, minx,2=2\min\\{x, 2\\} = 2. So the left-hand side becomes x2x - 2.
On the right-hand side: x+2=x+2|x + 2| = x + 2, x2=x2|x - 2| = x - 2. So the right-hand side becomes (x+2)(x2)=4(x + 2) - (x - 2) = 4.
Equating both sides:
x2=4    x=6x - 2 = 4 \implies x = 6
Thus, x=6x = 6 is a solution for x>2x > 2.

Case 2 : x<2x < 2. In this case: maxx,2=2\max\\{x, 2\\} = 2, minx,2=x\min\\{x, 2\\} = x. So the left-hand side becomes 2x2 - x.
On the right-hand side: x+2=x+2|x + 2| = x + 2, x2=2x|x - 2| = 2 - x. So the right-hand side becomes (x+2)(2x)=2x(x + 2) - (2 - x) = 2x.
Equating both sides:
2x=2x    2=3x    x=232 - x = 2x \implies 2 = 3x \implies x = \frac{2}{3}
Thus, x=23x = \frac{2}{3} is a solution for x<2x < 2.

Conclusion: The solutions are x=6x = 6 and x=23x = \frac{2}{3}, so the number of distinct real solutions is 2.