Class 8 RS Aggarwal Mathematics Linear Equations solutions - free PDF download
FAQs on RS Aggarwal Class 8 Mathematics Solutions for Chapter-8 Linear Equations
1. How do you solve a typical linear equation from Exercise 8A of RS Aggarwal Class 8 Maths?
To solve a basic linear equation from RS Aggarwal's Chapter 8, where the variable is on one side, you should follow these steps:
- Isolate the variable: The main goal is to get the variable (like 'x') by itself on one side of the equation.
- Use transposition: Move the constant terms to the other side of the 'equals' sign. When you move a term, its sign changes (e.g., '+' becomes '-', and '×' becomes '÷').
- Simplify: Perform the necessary arithmetic operations to find the value of the variable. For example, in the equation 2x + 5 = 15, you would first transpose 5 to get 2x = 15 - 5, which simplifies to 2x = 10. Finally, you divide by 2 to get x = 5.
2. What is the correct method for solving equations with variables on both sides, as found in RS Aggarwal Chapter 8?
When solving equations with variables on both sides (e.g., 5x - 3 = 3x + 7), the correct method is to consolidate the terms. The steps are:
- Group variable terms: Use the transposition method to bring all terms with the variable to one side of the equation (usually the left-hand side).
- Group constant terms: Move all the constant terms (numbers without variables) to the opposite side.
- Simplify both sides: Combine the like terms. In our example, 5x - 3x = 7 + 3, which simplifies to 2x = 10.
- Solve for the variable: Perform the final division or multiplication to find the value of the variable, which here is x = 5.
3. How should word problems from RS Aggarwal Class 8 Chapter 8 be translated into linear equations?
Translating a word problem into a mathematical equation is a key skill. The correct approach involves these four steps:
- Identify the Unknown: Read the problem carefully to understand what you need to find. Assign a variable, like 'x' or 'y', to this unknown quantity.
- Formulate Expressions: Break down the sentences in the problem and translate them into mathematical expressions involving the variable. For example, "five more than a number" becomes "x + 5".
- Create the Equation: Find the statement of equality in the problem that connects the expressions. For instance, if "five more than a number is 20," the equation becomes x + 5 = 20.
- Solve the Equation: Use the standard methods of solving linear equations to find the value of the variable, which will be the answer to the word problem.
4. Why is it important to verify the solution after solving a linear equation in Chapter 8?
Verifying your solution is a crucial final step. The primary reason is to ensure accuracy. By substituting the value you found for the variable back into the original equation, you can check if the Left-Hand Side (LHS) equals the Right-Hand Side (RHS). If they match, your solution is correct. This process helps you catch any calculation errors made during transposition or simplification. For exams, this simple check can be the difference between a right and wrong answer, helping secure full marks.
5. How do you solve linear equations involving fractions in RS Aggarwal Class 8 Maths?
To solve linear equations that contain fractions, the most effective method is to eliminate the denominators first. The step-by-step process is:
- Find the Least Common Multiple (LCM) of all the denominators in the equation.
- Multiply every term on both sides of the equation by this LCM. This will cancel out all the denominators.
- You will be left with a simpler linear equation without any fractions.
- Solve this new equation using the standard transposition and simplification methods to find the value of the variable.
6. What is a common mistake students make when solving equations with brackets, like 3(x - 2) = 15?
A very common mistake is related to the distributive property. Many students incorrectly multiply the number outside the bracket with only the first term inside, for example, writing 3x - 2 = 15. The correct method requires you to multiply the outer number (3) with every term inside the bracket. The correct first step is 3 * x - 3 * 2 = 15, which simplifies to 3x - 6 = 15. Forgetting to multiply all terms is a frequent source of error.
7. How do the step-by-step solutions for RS Aggarwal Chapter 8 improve exam performance?
Following detailed, step-by-step solutions for Chapter 8 helps in multiple ways. Firstly, it teaches the systematic approach required to solve problems, which is essential for earning full marks in exams. Secondly, by repeatedly practising the correct methodology, you strengthen your understanding of core algebraic concepts like transposition and simplification. This builds a strong foundation, reduces careless errors, and increases your speed and confidence in solving any linear equation during the exam.
8. What is the fundamental difference between an 'expression' and an 'equation' in this chapter?
The fundamental difference lies in the presence of an equality sign (=).
- An algebraic expression is a combination of variables and constants connected by mathematical operators, but it does not have an equals sign. For example, 5x + 9 is an expression. You can only simplify or evaluate it.
- An equation, on the other hand, states that two expressions are equal. For example, 5x + 9 = 24 is an equation. The goal with an equation is to 'solve' it—to find the specific value of the variable that makes the statement true.











