TEACHING AID ON ALGEBRAIC METHODS

1. DIFFERENT PROBLEMS

2.  10 added to thrice a number makes 5 times
the number. What is the number?
3x + 10 = 5x ….....(1)
3x + 2x = 5x ……..(2)
From (1) & (2),
2x = 10
x = 10÷2
= 5

3. 36 added to 13 times a number gives
31 times the number. What is the
number?
13x + 36 = 31x …....(1)
13x + 18x = 31x ……..(2)
From (1) & (2),
18x = 36
x = 36 ÷18
= 2

4.  12 added to 3 times a number is equal to 2 added
to 5 times the number. What is the number?
3x + 12 = 5x + 2
3x + 12 = 3x + 2x + 2
2x + 2 = 12
2x = 12 – 2
= 10
x = 10 ÷ 2
= 5

5. 1) 3x + 10 = 5x
2) 13x + 36 = 31x
3) 3x + 12 = 5x + 2
In these expressions, two
operations on the unknown number
gives the same result.

7.  The age of Appu’s mother is 9 times that of
Appu. After 9 years, it would be 3 times
that of him. What are their ages now?
Let the age of Appu be x
Age of mother = 9x
After 9 years,
Age of Appu = x + 9
Age of mother = 9x + 9

8. Age of mother = 3 times of Appu’s age
9x + 9 = 3(x + 9)
9x + 9 = 3x + 27
9x – 3x = 27 – 9
6x = 18
x = 18 ÷ 6
= 3
Age of Appu = 3
Age of mother = 27