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
We are given the equation maxx,2−minx,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,2−minx,2 represents the absolute difference between x and 2, i.e., ∣x−2∣.
The right-hand side of the equation ∣x+2∣−∣x−2∣ is more complicated; so we need to analyze it case by case based on the value of x.
Case 1 : x>2. In this case: maxx,2=x, minx,2=2. So the left-hand side becomes x−2.
On the right-hand side: ∣x+2∣=x+2, ∣x−2∣=x−2. So the right-hand side becomes (x+2)−(x−2)=4.
Equating both sides:
x−2=4⟹x=6
Thus, x=6 is a solution for x>2.
Case 2 : x<2. In this case: maxx,2=2, minx,2=x. So the left-hand side becomes 2−x.
On the right-hand side: ∣x+2∣=x+2, ∣x−2∣=2−x. So the right-hand side becomes (x+2)−(2−x)=2x.
Equating both sides:
2−x=2x⟹2=3x⟹x=32
Thus, x=32 is a solution for x<2.
Conclusion: The solutions are x=6 and x=32, so the number of distinct real solutions is 2.
Solution
We are given the equation maxx,2−minx,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,2−minx,2 represents the absolute difference between x and 2, i.e., ∣x−2∣.
The right-hand side of the equation ∣x+2∣−∣x−2∣ is more complicated; so we need to analyze it case by case based on the value of x.
Case 1 : x>2. In this case: maxx,2=x, minx,2=2. So the left-hand side becomes x−2.
On the right-hand side: ∣x+2∣=x+2, ∣x−2∣=x−2. So the right-hand side becomes (x+2)−(x−2)=4.
Equating both sides:
x−2=4⟹x=6
Thus, x=6 is a solution for x>2.
Case 2 : x<2. In this case: maxx,2=2, minx,2=x. So the left-hand side becomes 2−x.
On the right-hand side: ∣x+2∣=x+2, ∣x−2∣=2−x. So the right-hand side becomes (x+2)−(2−x)=2x.
Equating both sides:
2−x=2x⟹2=3x⟹x=32
Thus, x=32 is a solution for x<2.
Conclusion: The solutions are x=6 and x=32, so the number of distinct real solutions is 2.