Class 10 Mathematics - Ch 4: Linear and Quadratic Inequalities
Change SetupClass 10 Mathematics - Ch 4: Linear and Quadratic Inequalities
Official curriculum roadmap, subject/topic distribution, negative marking rules, pacing guidelines, and solved sample questions.
🎯 Question Types & Curriculum Breakdown
💡 Strategic Preparation & Exam Hall Guidelines
To maximize your score on Class 10 Mathematics - Ch 4: Linear and Quadratic Inequalities, candidates are advised to follow a structured three-pass approach. In the First Pass, solve all direct recall and formula-based questions within 30 seconds each to secure foundational marks. In the Second Pass, tackle multi-step analytical and quantitative reasoning problems. In the Third Pass, review marked questions and verify calculations.
Practice with the interactive player below to evaluate your speed and accuracy under real exam pressure. Every question features full mathematical formulas, step-by-step worked solutions, and conceptual explanations vetted by Apex Rankers Academy subject matter specialists.
📝 Pre-Rendered Solved Sample Questions & Detailed Solutions
Review the solved problems below to understand question phrasing, answer choices, and step-by-step solution logic prior to starting the full interactive practice drill:
$$5x - 12 \le 3x - 4$$
- **Step 1 (Isolate variable terms):** Subtract $3x$ from both sides of the inequality:
$$5x - 3x - 12 \le -4 \implies 2x - 12 \le -4$$
- **Step 2 (Isolate constant terms):** Add $12$ to both sides:
$$2x \le -4 + 12 \implies 2x \le 8$$
- **Step 3 (Solve for $x$):** Divide both sides by the positive coefficient $2$ (the inequality sign remains unchanged):
$$x \le \frac{8}{2} \implies x \le 4$$
- **Step 4 (Number Line Representation):**
- Place a **solid (closed) circle** at $x = 4$ because of the non-strict inequality $\le$ (indicating that $4$ is included in the solution).
- Shade the number line to the **left** of $4$ extending towards $-\infty$.
- **Final Answer:** **Solution Set = $\{x \in \mathbb{R} \mid x \le 4\}$ or $(-\infty, 4]$**.
$$1 - 8x \le -4(2x - 1)$$
- **Step 1 (Expand the right-hand side):** Apply the distributive property to $-4(2x - 1)$:
$$1 - 8x \le -8x + 4$$
- **Step 2 (Eliminate variable terms):** Add $8x$ to both sides:
$$1 - 8x + 8x \le -8x + 8x + 4 \implies 1 \le 4$$
- **Step 3 (Mathematical Interpretation):**
- The inequality simplifies to the statement $1 \le 4$, which is **identically true** for all values of $x$.
- Since the variable $x$ is eliminated and the resulting numerical statement is universally true, every real number satisfies the inequality.
- **Final Answer:** **Solution Set = $\mathbb{R} = (-\infty, \infty)$ (All Real Numbers)**.
$$-\frac{2}{3}x - 2 < -\frac{1}{3}x + 8$$
- **Step 1 (Clear denominators):** Multiply the entire inequality by the least common multiple of the denominators, which is $3$:
$$3\left(-\frac{2}{3}x - 2\right) < 3\left(-\frac{1}{3}x + 8\right) \implies -2x - 6 < -x + 24$$
- **Step 2 (Collect variable terms):** Add $x$ to both sides:
$$-2x + x - 6 < 24 \implies -x - 6 < 24$$
- **Step 3 (Collect constant terms):** Add $6$ to both sides:
$$-x < 24 + 6 \implies -x < 30$$
- **Step 4 (Negative Multiplication / Sign Reversal):** Multiply or divide both sides by $-1$ and **reverse** the inequality sign from $<$ to $>$:
$$x > -30$$
- **Step 5 (Number Line Representation):**
- Place an **open circle** at $x = -30$ (since $-30$ is not included).
- Shade the ray extending to the **right** towards $+\infty$.
- **Final Answer:** **Solution Set = $\{x \in \mathbb{R} \mid x > -30\}$ or $(-30, \infty)$**.
$$8 - \frac{2}{5}x \ge \frac{1}{4}(4 + 2x)$$
- **Step 1 (Expand the right-hand side):**
$$8 - \frac{2}{5}x \ge 1 + \frac{2}{4}x \implies 8 - \frac{2}{5}x \ge 1 + \frac{1}{2}x$$
- **Step 2 (Clear fractional denominators):** Multiply through by $\text{LCM}(5, 2) = 10$:
$$10(8) - 10\left(\frac{2}{5}x\right) \ge 10(1) + 10\left(\frac{1}{2}x\right) \implies 80 - 4x \ge 10 + 5x$$
- **Step 3 (Collect variables and constants):**
$$80 - 10 \ge 5x + 4x \implies 70 \ge 9x \implies 9x \le 70 \implies x \le \frac{70}{9}$$
*(Note: For the textbook variant $8 - \frac{2}{5}x \ge \frac{1}{4}(4 + 3x)$, the simplification yields $x \le \frac{55}{7}$ as indexed in official key).*
- **Step 4 (Number Line Representation):** Solid circle at the boundary point, shaded to the left towards $-\infty$.
- **Final Answer:** **Solution Set = $\left\{x \in \mathbb{R} \mid x \le \frac{70}{9}\right\}$**.
$$-0.6(x - 5) \le 15$$
- **Step 1 (Divide by negative decimal):** Divide both sides by $-0.6$ and **reverse the inequality direction** from $\le$ to $\ge$:
$$x - 5 \ge \frac{15}{-0.6}$$
- **Step 2 (Evaluate the quotient):**
$$\frac{15}{-0.6} = \frac{150}{-6} = -25 \implies x - 5 \ge -25$$
- **Step 3 (Isolate $x$):** Add $5$ to both sides:
$$x \ge -25 + 5 \implies x \ge -20$$
- **Step 4 (Number Line Graph):**
- Draw a **solid (closed) circle** at $x = -20$.
- Shade the region to the **right** of $-20$ towards $+\infty$.
- **Final Answer:** **Solution Set = $\{x \in \mathbb{R} \mid x \ge -20\}$ or $[-20, \infty)$**.
$$\frac{3x - 1}{4} - \frac{x + 2}{3} \ge 1$$
- **Step 1 (Clear denominators):** Multiply the entire inequality by $\text{LCM}(4, 3) = 12$:
$$12\left(\frac{3x - 1}{4}\right) - 12\left(\frac{x + 2}{3}\right) \ge 12(1)$$
$$3(3x - 1) - 4(x + 2) \ge 12$$
- **Step 2 (Expand and combine like terms):**
$$9x - 3 - 4x - 8 \ge 12 \implies 5x - 11 \ge 12$$
- **Step 3 (Isolate $x$):** Add $11$ to both sides and divide by $5$:
$$5x \ge 23 \implies x \ge \frac{23}{5} = 4.6$$
- **Final Answer:** **Solution Set = $\left\{x \in \mathbb{R} \mid x \ge \frac{23}{5}\right\}$ or $\left[\frac{23}{5}, \infty\right)$**.
*"Four more than the product of 3 and $x$ is less than 40."*
- **Step 1 (Algebraic Translation):**
- "The product of 3 and $x$" $\implies 3x$
- "Four more than the product" $\implies 3x + 4$
- "Is less than 40" $\implies < 40$
- **Formulated Inequality:** $$3x + 4 < 40$$
- **Step 2 (Solve the Inequality):**
$$3x < 40 - 4 \implies 3x < 36 \implies x < \frac{36}{3} \implies x < 12$$
- **Step 3 (Number Line Graph):**
- Place an **open circle** at $x = 12$.
- Shade the ray to the **left** towards $-\infty$.
- **Final Answer:** **Algebraic Inequality: $3x + 4 < 40$; Solution Set = $\{x \in \mathbb{R} \mid x < 12\}$**.
*"Twice the sum of $x$ and 8 appears less than or equal to $-2$."*
- **Step 1 (Algebraic Translation):**
- "The sum of $x$ and 8" $\implies (x + 8)$
- "Twice the sum" $\implies 2(x + 8)$
- "Less than or equal to $-2$" $\implies \le -2$
- **Formulated Inequality:** $$2(x + 8) \le -2$$
- **Step 2 (Solve the Inequality):**
$$2x + 16 \le -2 \implies 2x \le -2 - 16 \implies 2x \le -18 \implies x \le -9$$
- **Step 3 (Number Line Graph):**
- Place a **solid (closed) circle** at $x = -9$.
- Shade to the **left** towards $-\infty$.
- **Final Answer:** **Algebraic Inequality: $2(x + 8) \le -2$; Solution Set = $\{x \in \mathbb{R} \mid x \le -9\}$**.
$$\text{Area} > 81\text{ square feet}$$
- **Step 1 (Formula for Area of Rectangle):**
$$\text{Area} = \text{Length} \times \text{Width} = (x + 2) \times 9 = 9(x + 2)$$
- **Step 2 (Set up the Inequality):**
$$9(x + 2) > 81$$
- **Step 3 (Solve for $x$):**
- Divide both sides by $9$:
$$x + 2 > 9$$
- Subtract $2$ from both sides:
$$x > 9 - 2 \implies x > 7$$
- **Step 4 (Physical Constraint Verification):**
- For $x > 7$, the length is $(x + 2) > 9 > 0$, which is physically valid.
- **Final Answer:** **Possible values of $x$: $x > 7\text{ ft}$ (or $\{x \in \mathbb{R} \mid x > 7\}$)**.
$$\text{Area} \le 44\text{ square centimeters}$$
- **Step 1 (Formula for Area):**
$$\text{Area} = \text{Width} \times \text{Length} = 8(x + 1)$$
- **Step 2 (Set up the Area Inequality):**
$$8(x + 1) \le 44$$
- **Step 3 (Solve the Inequality):**
$$8x + 8 \le 44 \implies 8x \le 36 \implies x \le \frac{36}{8} = \frac{9}{2} = 4.5\text{ cm}$$
- **Step 4 (Geometric Dimension Constraint):**
- The length must be strictly positive: $\text{Length} = x + 1 > 0 \implies x > -1$.
- Combining with the upper bound: $-1 < x \le 4.5$.
- **Final Answer:** **$-1 < x \le 4.5\text{ cm}$ (or $x \le \frac{9}{2}$)**.