Chapter 18.3 (Mathematics 5)

Forming Simple Equations (3)

Forming simple equations

Group Activity 2

In groups of four:

  1. Take a number x.
  2. Multiply x by 3.
  3. Subtract 7 from the product.
  4. If the result is 8, form an equation to represent the information.
  5. Share and discuss your results with other groups.

Example 4

In a meeting, there were 120 people. The number of men was two times that of women. Form an equation to represent this information.

  1. Let the number of women be w.
  1. The number of men was

2 × w = 2w

  1. Total number of men and women was

w + 2w = 3w

  1. Equation

2w = 120

Exercise C

  1. In a class there are 27 pupils. The number of girls is two times that of boys.
    1. Number of boys b.
    2. Number of girls
      2   =  
    3. Boys and girls together
         = 
    4. Equation
       = 27
  2. There are 21 fruits in a basket. The number of oranges is twice that of mangoes.
    1. Number of mangoes m.
    2. Number of oranges
         =  
    3. Mangoes and oranges together
         = 
    4. Equation
       = 
  1. The price of a book and a pencil is Sh 120. The price of the book is thrice the price of the pencil.
    1. The price of the pencil is p.
    2. The price of the book
         =  
    3. The price of the pencil and of the book together
         = 
    4. Equation
       = 
  2. Bekele and Mwendwa shared Sh 400. Bekele got three times of what Mwendwa got.
    1. Mwenda got Sh m.
    2. Sekele got
         =  
    3. Total money shared
         = 
    4. Equation
       = 
  1. I think of a number P. Multiply the number by 6, the answer is 48.
    • Equation
       = 
  2. In a book shelf there are 36 exercise books. The number of squared exercise books is three times the number of ruled exercise books (r).
    • Equation
       =