Basics & LogarithmsmediumFree

Basics & Logarithms: Number Negative Integer Solutions Equation

JEE Maths question with a full step-by-step solution.

Question
Number of negative integer solutions of the equation x+1x+3x12x2=x+2|x+1| - |x| + 3|x-1| - 2|x-2| = x+2 is
Solution
Answer: 1
Case 1: x2x \geq 2: (x+1)x+3(x1)2(x2)=x+2    x+2=x+2(x+1) - x + 3(x-1) - 2(x-2) = x+2 \implies x+2 = x+2 True for all x2x \geq 2. No negative integers here. Case 2: 1x<21 \leq x < 2: (x+1)x+3(x1)2(2x)=x+2    5x6=x+2    x=2(x+1) - x + 3(x-1) - 2(2-x) = x+2 \implies 5x-6 = x+2 \implies x = 2 Not in [1,2)[1,2). No solution. Case 3: 0x<10 \leq x < 1: (x+1)x+3(1x)2(2x)=x+2    x=x+2    x=1(x+1) - x + 3(1-x) - 2(2-x) = x+2 \implies -x = x+2 \implies x = -1 Not in [0,1)[0,1). No solution. Case 4: 1x<0-1 \leq x < 0: (x+1)+x+3(1x)2(2x)=x+2    x+0=x+2    0=2(x+1) + x + 3(1-x) - 2(2-x) = x+2 \implies x+0 = x+2 \implies 0 = 2 Contradiction. No solution. Case 5: x<1x < -1: (x+1)+x+3(1x)2(2x)=x+2    x2=x+2    x=2-(x+1) + x + 3(1-x) - 2(2-x) = x+2 \implies -x-2 = x+2 \implies x = -2 x=2<1x = -2 < -1. Valid. Verify: 12+3324=12+98=0=2+2|-1|-|-2|+3|-3|-2|-4| = 1-2+9-8 = 0 = -2+2. Confirmed. Answer: 1
Still stuck on this question?Ask your doubt on WhatsApp
Similar questions

Solve more, learn faster

Sign up free to solve more JEE Maths questions and explore doMath — timed drills, mastery sprints, bookmarks, and chapter-wise progress tracking.