Welcome to Class 8 Maths MCQ – Linear Equations in One Variable. These MCQs (Multiple Choice Questions) are created based on the latest CBSE syllabus offering valuable assistance for exam preparation and testing your knowledge. Each question is complemented by the correct answer and a concise explanation.
1. Which of the following is a linear equation in one variable?
Answer:
Explanation:
A linear equation in one variable is of the form ax + b = 0, where a and b are real numbers, and a ≠ 0.
2. The solution to the equation 3x – 5 = 16 is:
Answer:
Explanation:
By adding 5 and then dividing by 3, we get x = 7.
3. If 5 times a number increased by 2 gives 12, the number is:
Answer:
Explanation:
Let the number be x, then 5x + 2 = 12. Solving gives x = 2.
4. The equation representing "Three times a number decreased by 8 is 19" is:
Answer:
Explanation:
The given statement translates to the equation 3x – 8 = 19.
5. The value of x in 2(x + 5) = 3x – 6 is:
Answer:
Explanation:
Expanding and simplifying, 2x + 10 = 3x – 6. Solving for x gives x = 16.
6. The coefficient of x in the equation 7x – 4 = 28 is:
Answer:
Explanation:
The coefficient of x is the number multiplied by x, which is 7.
7. An equation with no solution is called:
Answer:
Explanation:
An inconsistent equation does not have any solution.
8. The sum of three times a number and 2 is 11. The number is:
Answer:
Explanation:
Let the number be x, then 3x + 2 = 11. Solving gives x = 3.
9. A linear equation in one variable will have:
Answer:
Explanation:
A linear equation in one variable always has one unique solution.
10. If half of a number increased by 7 is 10, then the number is:
Answer:
Explanation:
Let the number be x, then x/2 + 7 = 10. Solving for x gives x = 6.
11. The solution of the equation x/3 = 5 is:
Answer:
Explanation:
Multiplying both sides by 3 gives x = 15.
12. The value of x that satisfies the equation 4x – 3 = 5x + 6 is:
Answer:
Explanation:
Simplifying the equation gives x = -9.
13. The equation representing "Five less than twice a number is 15" is:
Answer:
Explanation:
The given statement translates to the equation 2x – 5 = 15.
14. The solution of the equation 5 – 2x = 3x – 6 is:
Answer:
Explanation:
Grouping like terms and simplifying, we get x = 11/5.
15. A number decreased by 3 is 12. The number is:
Answer:
Explanation:
Let the number be x, then x – 3 = 12. Solving gives x = 15.
16. The equation representing "A number increased by 5 is 10" is:
Answer:
Explanation:
The given statement translates directly to x + 5 = 10.
17. Four times a number, decreased by 7, gives 21. The number is:
Answer:
Explanation:
Let the number be x, then 4x – 7 = 21. Solving for x gives x = 7.
18. An equation that is true for every value of the variable is called:
Answer:
Explanation:
An identity is an equation that holds true for every possible value of the variable.
19. The value of x in 2x = 4x – 12 is:
Answer:
Explanation:
Simplifying the equation, we get x = 6.
20. The sum of a number and 5 times its additive inverse is:
Answer:
Explanation:
Let the number be x. Its additive inverse is -x. The sum is x + 5(-x) = 0.