Q.Solve 35−2x≤6x−5.
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Linear Inequality Solutions – A First Look
Imagine you're standing on a number line. You know exactly where the number 5 is. But what if I asked you to stand on "all numbers greater than 5"? You can't stand on all of them at once — they stretch infinitely to the right. That's the core idea of an inequality: instead of one exact point, you get a whole region of possible values.
A linear inequality is just like a linear equation (ax+b=0), but instead of an equals sign, you have one of these: <, >, ≤, or ≥. The solution is not a single number — it's an interval (or a union of intervals) on the number line.
From Equation to Inequality
Start with a simple equation:
2x+3=7
Solve it: 2x=4⟹x=2. One point.
Now change it to an inequality:
2x+3>7
Solve it the same way — but the meaning changes. Subtract 3: 2x>4. Divide by 2: x>2.
The solution is all numbers greater than 2. On a number line, you draw an open circle at 2 (because 2 itself is not included) and shade everything to the right.
If you multiply or divide both sides of an inequality by a negative number, the inequality sign reverses. For example: −x<5 becomes x>−5. This is the single most common mistake students make.
The Four Types of Solutions
| Inequality | Meaning | Number line representation |
|---|---|---|
| x>a | All numbers strictly greater than a | Open circle at a, shade right |
| x≥a | All numbers greater than or equal to a | Closed (filled) circle at a, shade right |
| x<a | All numbers strictly less than a | Open circle at a, shade left |
| x≤a | All numbers less than or equal to a | Closed circle at a, shade left |
The solution set is usually written in interval notation:
- x>2 → (2,∞)
- x≤−3 → (−∞,−3]
Parentheses ( or ) mean the endpoint is not included. Brackets [ or ] mean it is included.
Solving a Linear Inequality: Step by Step
Solve 3x−5≤7x+3.
-
Bring variable terms to one side:
3x−5−7x≤3
−4x−5≤3
-
Isolate the variable term:
−4x≤8
-
Divide by the coefficient (here it's −4, so reverse the sign):
x≥−2
The solution is x≥−2, or in interval notation: [−2,∞).
Always check your answer by testing a number from the solution set. For x≥−2, test x=0: 3(0)−5=−5 and 7(0)+3=3. Is −5≤3? Yes. Now test a number outside, say x=−3: 3(−3)−5=−14 and 7(−3)+3=−18. Is −14≤−18? No — so the inequality fails, confirming our solution is correct.
Why This Matters …
Concept: Linear Inequality Solutions
We solve by clearing denominators and isolating x, remembering that multiplying or dividing by a negative reverses the inequality.
Multiply both sides by 6 (the LCD of 3 and 6):
6⋅35−2x≤6⋅(6x−5)
2(5−2x)≤x−30
10−4x≤x−30 …
Clear the fractions, gather the x-terms so the coefficient stays positive, and solve. The solution is x≥8.
Clear fractions. The LCD of 3 and 6 is 6:
6⋅35−2x≤6⋅6x−6⋅5⟹2(5−2x)≤x−30.
Expand.
10−4x≤x−30.
Collect x-terms on the right (keeps the coefficient positive, so no sign flip). Add 4x to both sides:
10≤5x−30.
Isolate x. Add 30: …
Showing the 12 most recent of 36 on this concept.
- KEAM 2026Set eng-2026-04174 marksMCQQ.The solution set of the inequality 6(2x+3)+x>53−2x is (A) (37,∞) (B) (−∞,37) (C) (37,2) (D) (−2,37) (E) (−37,∞)
›Reveal solutionSolution
Expand and collect terms: 15x>35, so x>37.
Expand the left side:
6(2x+3)+x=12x+18+x=13x+18.
The inequality becomes …
- KEAM 2026Set eng-2026-04174 marksMCQQ.In a right-angled trapezium ABCD, ∠A=90∘, ∠D=90∘, AB=7a+1, CD=3a+1 and AD=3a. If the perimeter of the trapezium is greater than 56 but less than 92, then the range of possible values of a, is (A) 4<a<211 (B) 27<a<5 (C) 3<a<29 (D) 3<a<7 (E) 3<a<5
›Reveal solutionSolution
The perimeter is 18a+2; solving 56<18a+2<92 gives 3<a<5.
In the right-angled trapezium, AB∥CD with the perpendicular leg AD=3a. The horizontal offset between the parallel sides is AB−CD=(7a+1)−(3a+1)=4a, so the slant side is
BC=(4a)2+(3a)2=25a2=5a.
The perimeter is …
- KEAM 2026Set eng-2026-04184 marksMCQQ.The set of all x satisfying the inequality 8+3x>4(x−3)+2 is (A) (18,∞) (B) (20,∞) (C) (−∞,18) (D) (−∞,20) (E) (−20,18)
›Reveal solutionSolution
Solving 8+3x>4(x−3)+2 yields x<18.
8+3x>4(x−3)+2=4x−12+2=4x−10.
Bring terms together:
8+10>4x−3x⇒18>x. …
- KEAM 2026Set eng-2026-04194 marksMCQQ.Let x be a real number such that 5<∣x−1∣<15. Then (A) −18<x<−3 or 3<x<19 (B) −14<x<−3 or 6<x<17 (C) −16<x<−2 or 6<x<20 (D) −14<x<−4 or 6<x<16 (E) −10<x<−1 or 3<x<18
›Reveal solutionSolution
Solve the two-sided inequality: −14<x<−4 or 6<x<16.
Upper bound ∣x−1∣<15: −15<x−1<15⇒−14<x<16.
Lower bound ∣x−1∣>5: x−1>5 or x−1<−5⇒x>6 or x<−4. …
- KEAM 2026Set eng-2026-04194 marksMCQQ.Let x be a real number such that x−2x−3≥1. Then the solution set of the inequality is (A) (−∞,3) (B) (−∞,2) (C) [0,∞) (D) (−9,∞) (E) (0,8)
›Reveal solutionSolution
Subtract 1 and analyse the sign: solution is (−∞,2).
Rearrange.
x−2x−3−1≥0⇒x−2(x−3)−(x−2)≥0⇒x−2−1≥0. …
- KEAM 2026Set eng-2026-04204 marksMCQQ.If x+22x−10≥x−5 then x lies in (A) (−∞,−1)∪[0,6] (B) (−∞,−2)∪[−1,5] (C) (−∞,−2)∪[0,10] (D) (−∞,0)∪[0,5] (E) (−∞,−2)∪[0,5]
›Reveal solutionSolution
Factoring 2x−10=2(x−5) and moving everything to one side yields −x+2x(x−5)≥0, i.e. x+2x(x−5)≤0. A sign chart gives x<−2 or 0≤x≤5.
Start from x+22x−10≥x−5. Since 2x−10=2(x−5):
x+22(x−5)−(x−5)≥0⇒(x−5)[x+22−1]≥0.
Simplify the bracket:
x+22−(x+2)=x+2−x,
so
(x−5)⋅x+2−x≥0⟺x+2x(x−5)≤0.
Critical points: x=−2 (excluded), x=0, x=5. Sign of x+2x(x−5): …
- KEAM 2026Set eng-2026-04204 marksMCQQ.If 10<∣x+10∣≤25, then x lies in (A) [−45,−20)∪(0,15] (B) [−35,−25)∪(0,15] (C) [−35,−20)∪(0,15] (D) [−35,−20)∪(0,25] (E) [−35,−10)∪(0,15]
›Reveal solutionSolution
Substitute y=x+10. The double inequality 10<∣y∣≤25 means y∈[−25,−10)∪(10,25]. Converting back (x=y−10) gives x∈[−35,−20)∪(0,15].
Let y=x+10, so the condition is 10<∣y∣≤25.
This breaks into:
∣y∣>10⇒y<−10 or y>10,
∣y∣≤25⇒−25≤y≤25. …
- KEAM 2026Set eng-2026-04204 marksMCQQ.A number x is randomly chosen from the set of natural numbers less than or equal to 100. Then the probability of the event that the chosen number satisfies the inequality x−30(x−15)(x−70)≥0, is (A) 0.36 (B) 0.47 (C) 0.48 (D) 0.49 (E) 0.46
›Reveal solutionSolution
Sign-analyse x−30(x−15)(x−70)≥0 over integers 1–100 (x=30 excluded).
Critical points: 15,30,70 (with x=30 making the denominator zero).
- x<15: expression <0.
- 15≤x<30: ≥0 (equals 0 at x=15). Integers 15,…,29 → 15 values.
- 30<x<70: <0. …
- KEAM 2026Set eng-2026-04214 marksMCQQ.If (x−1)(x2−5x+7)<(x−1), then x belongs to (A) (−∞,−1)∪(2,3) (B) (−∞,−1]∪[2,3] (C) (−∞,1)∪(2,3) (D) (−∞,1)∪[2,3) (E) (−∞,1)∪(2,3]
›Reveal solutionSolution
Bringing everything to one side factors as (x−1)(x−2)(x−3)<0, giving (−∞,1)∪(2,3).
(x−1)(x2−5x+7)−(x−1)<0⇒(x−1)(x2−5x+6)<0⇒(x−1)(x−2)(x−3)<0. …
- KEAM 2026Set eng-2026-04214 marksMCQQ.The solution set of x+x1>2 is (A) R (B) R−{0} (C) R−{1,−1} (D) R−{−1} (E) R−{−1,0,1}
›Reveal solutionSolution
By AM–GM ∣x+1/x∣≥2 with equality only at x=±1; excluding those and x=0 gives R−{−1,0,1}.
For real x=0, x+x1≥2, with equality exactly when x=±1. The strict inequality >2 therefore holds for all x except x=±1; al …
- KEAM 2026Set eng-2026-04224 marksMCQQ.If 421x−6−9≤0 and 3x−1+1≥0,x∈R, then x lies in the interval (A) [−2,1] (B) [−2,2] (C) [−1,2] (D) [2,4] (E) [−2,4]
›Reveal solutionSolution
Solve each inequality separately and intersect.
First: 421x−6≤9⇒21x−6≤36⇒21x≤42⇒x≤2. …
- KEAM 2026Set eng-2026-04224 marksMCQQ.If ∣2x−3∣<5,x∈R, then x lies in the interval (A) [−1,1] (B) [−1,4] (C) (−1,4) (D) (−2,4) (E) [−2,4]
›Reveal solutionSolution
Remove the modulus with a two-sided inequality; strict < gives an open interval.
∣2x−3∣<5 means −5<2x−3<5.
Add 3: −2<2x<8. Divide by 2: −1<x<4. …
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