Linear Equations In One Variable – Class 8/Maths.

Chapter 2 of NCERT/CBSE Class 8 Maths is about Linear Equations in One Variable. Here in this chapter you can find practice problems for this chapter.

CBSE CLASS 8 MATHEMATICS/Model Questions
Linear Equations in One Variable – Chapter 2
Choose the correct answer from the options given below:

1. Which of the following is a linear equation in one variable?
   A. 2x
   B. 3y -7z
   C. x + y + z
2. The solution of the equation 2x – 3 = 7 is ———
   A. 3
   B. 5
   C. 7
3. Solve the equation: 3x = 12
   A. 3
   B. 4
   C. 5
4. Which of the following is an equation?
   A. 3x + y
   B. y + 3 = 10
   C. 3xyz
5. The highest power of a variable in a linear equation is ——-
   A. 0
   B. 1
   C. 2
   Answer the following:
6. Solve the equation: 5x – 9 = 16
7. The perimeter of a rectangle is 16 cm and its width is 3cm. Find its length?
8. Check whether the linear equation 17 + 6p= 5 is true for p = -2.
9. The sum of two numbers is 26 and their difference is 14. Find the two numbers?
10. Convert the following statements into equations and solve?
    a) Subtract 5 from seven times a number x gives 16.
    b) Twice a number x added to 5 gives 25.

ANSWERS:

1. 2x
2. 5
3. 4
4. y + 3 = 10
5. 1
6. 5x – 9 = 16
   5x = 16 + 9
   5x = 25
   x = 25/5 = 5.
7. Given perimeter = 16 cm and width = 3 cm.
   Let the length of the rectangle be x.
   Then we know that perimeter = 2 (length + breadth)
   Therefore, 16 = 2(x + 3)
   16/2 = x + 3
   8 = x + 3
   x = 8 – 3 = 5
8. LHS = 17 + 6p
   Substitute p = -2, 17 + 6 (-2) = 17 + (-12) = 5 = RHS.
9. Let one number be x.
   Other number = 26 – x
   Given difference of these numbers is 14.
   ie, x – ( 26 – x) = 14
   x – 26 + x = 14
   2x = 14 + 26 = 40
   x = 40/2 = 20.
10. a) 7x – 5 = 16
    7x = 16 + 5 = 21
    x = 21/7 = 3
    b) 2x + 5 = 25
    2x = 25 – 5 = 20
    x = 20/2 = 10.