NCERT Solutions for Class 8 Maths Chapter 2 Linear Equations in One Variable Exercise 2.5

Examples From Chapter 2 Linear Equations in One Variable

Ex. 1 Mahesh’s father is 49 years old. He is 4 years older than three times Mahesh’s age. Determine Mahesh’s age?

Soln: If Mahesh’s age is x years

∴ Mahesh’s father's age =4+3x

Hence, 

49=4+3x

⟹3x=49−4

⟹x=45/3

=15

∴ Mahesh is 15 years old.

Ex. 2 When a natural number is increased by 12, it becomes equal to 160 times its reciprocal. Determine the number.

Soln: Let the number be x.

Then,

x+12=160×(1/x)​

x²+12x−160=0

(x+20)(x−8)=0

x=−20,8

Therefore, the required natural number is 8.