Question

The sum of the digits of a two-digit number is 3.
If we subtract 9 from the number, the digits are
interchanged. Find the original number. in one variable​

Answer 1

Answer:

21

Step-by-step explanation:

there are only 4 pairs which add up to 3

3 and 0 , 30

2 and 1 , 21

1 and 2 , 12

and

0 and 3 , 03

out of these only 21 fits the discription

Answer 2

Answer:

The original number is 21

Step-by-step explanation:

Let the digits of the number be x and y

The number becomes 10x + y

According to the question

x + y = 3

y = 3 - x

The number in one variable = 10x + (3-x)= = 10x - x + 3 = 9x + 3

Now the second condition

The number - 9 = 10y + x (the digits get interchanged)

9x + 3 - 9= 10(3 - x) + x

9x - 6= 30 - 10x + x

9x - 6 = 30 - 9x

9x + 9x = 30 + 6

18x = 36

x = 2

y = 3 - x = 3 - 2 = 1

The number is 21