Let’s learn how to convert a situation into an expression.

 

First

      we find variable in our situation

      and then make an expression.

Situation

Variable

Expression

Sarita has 10 more
marbles than Ameena.

Let

Marbles with Ameena = x

Marbles with Sarita

           = x + 10

Balu is 3 years
younger than Raju

Let

Raju’s Age = x years

Balu’s age

       = (x − 3) years

Bikash is twice
as old as Raju.

Let,

Raju’s age = x years

Bikash’s age

  = 2 × 𝑥

        = 2x years

Raju’s father’s age is 2 years more than 3 times Raju’s age.

Let

Raju’s Age = x years

Raju’s father's age

       = (3x + 2) years

How old will Susan
be 5 years from now?

Let,

Susan’s Age = y years

Susan’s age
after 5 years

       = (y + 5) years

How old was Susan
4 years ago ?

Let,

Susan’s Age = y years

Susan’s age
4 years ago

     = (y − 4) years

Price of wheat per kg is rupees 5 less

Let,

 Price of rice per kg

= p Rupees

Price of wheat per kg

      = (p − 5) rupees

Price of oil per litre
is 5 times the price of rice per kg.

Let,

 Price of rice per kg

     = p Rupees

Price of oil per litre

= 5p rupees

The speed of a bus is
10 km/hour more than
the speed of a truck
going on the same road.

Let,

Speed of truck

  = y km/hr

Speed of bus

= (y + 10) km/hr

Ali has twice as much apps as Nandan do.

Let,

Number of apps
with Nandan = x

No. of apps

with Ali = 2x

Rajshri has got 3 more certificates than Kamal.

Let,

 No: of certificates
that Kamal has = x

No: of certificates that Rajshri has

  = x + 3

Anthony has 10 toys less than Kabir

Let,

Number of toys with Kabir = x

Let,

Number of toys Anthony have = x - 10

Sumit's weight is one-third of his grandfather's weight

Let,

Weight of Sumit’s grand father = w

Weight of Sumit

  = w/3

  1. Chapter 11 Class 6 Algebra
  2. Concept wise

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.