An Overview of Class 8 Maths Linear Equations In One Variable Worksheets
FAQs on Class 8 Maths Linear Equations In One Variable Worksheets
1. What defines a 'Linear Equation in One Variable' and makes it important for Class 8 exams?
A linear equation in one variable is an algebraic equation where the highest power of the variable is 1. It can be written in the standard form ax + b = 0, where 'x' is the variable and 'a' and 'b' are numbers. These questions are fundamental in exams, often appearing as 1-mark questions to test basic concepts like identifying the variable and its power.
2. What is the step-by-step method to solve an equation like 3(t - 3) = 5(2t + 1) for a 2 or 3-mark question?
To solve an equation with variables on both sides, follow these exam-oriented steps for full marks:
Step 1: Simplify both sides of the equation by distributing the numbers outside the brackets. Here, it becomes 3t - 9 = 10t + 5.
Step 2: Transpose all terms with the variable to one side (e.g., LHS) and all constant terms to the other side (e.g., RHS). This gives 3t - 10t = 5 + 9.
Step 3: Combine like terms on both sides. The equation becomes -7t = 14.
Step 4: Solve for the variable by dividing both sides by its coefficient (-7). This yields t = -2.
3. What is the most common mistake students make when transposing terms in linear equations, and how can it be avoided?
The most common and critical mistake is forgetting to change the sign of a term when moving it from one side of the equals sign to the other. For example, moving '+7' from LHS to RHS should make it '-7'. To avoid this, always double-check the sign of every term you transpose. A good practice is to circle the term with its sign before moving it to remind yourself to flip the operation (addition becomes subtraction, multiplication becomes division, and vice versa).
4. What types of word problems are most expected in the CBSE Class 8 exam for 2025-26 from this chapter?
For the 2025-26 session, you can expect word problems that test your ability to form and solve a linear equation. These are often higher-mark questions (3-5 marks). Important types include:
Questions based on ages of people (e.g., father and son).
Problems involving consecutive integers or numbers.
Questions related to perimeter and dimensions of shapes like rectangles.
Problems about currency notes and their total value.
5. How can you verify your answer for a linear equation during an exam? Why is this step important?
To verify your solution, substitute the value of the variable you found back into the original equation. Caculate the Left-Hand Side (LHS) and the Right-Hand Side (RHS) separately. If LHS equals RHS, your solution is correct. This step is crucial in an exam because it helps you catch careless mistakes and ensures you secure full marks for the question, especially for high-value word problems.
6. How do you approach an important question type where the equation needs to be reduced to a linear form, like (x+1)/(2x+3) = 3/8?
This is a frequently asked question type. The key is to first convert it into a standard linear equation using the cross-multiplication method.
Step 1: Multiply the numerator of the LHS with the denominator of the RHS, and the numerator of the RHS with the denominator of the LHS. The equation becomes: 8(x + 1) = 3(2x + 3).
Step 2: Now it's a standard linear equation. Simplify it: 8x + 8 = 6x + 9.
Step 3: Transpose terms to get 8x - 6x = 9 - 8.
Step 4: Solve for x: 2x = 1, so x = 1/2.
7. For forming an equation from a word problem, what is the best strategy to select the 'variable'?
The best strategy is to identify the primary unknown quantity the question is asking you to find. This unknown quantity should be assigned the variable, usually 'x'. For instance, in an age problem asking for the son's current age, you should let 'the son's current age be x years'. All other unknown quantities in the problem can then be expressed in terms of 'x' based on the information given, making it easier to form the final equation.











