Question

THE sum of two digit number is 13.If the number is subtracted from one obtained by interchanging the digits ,the result is 45.Find the number?

Answer 1

Let us assume the digits be x and y

Then the two-digit number is 10x + y 

Given x + y = 13

           y = 13 – x --------------1

Interchange the two-digit number, get 10y + x

Given 10y + x – (10x + y) = 45

            9y – 9x = 45

              y – x = 5 --------------2

Substitute the value of y from eqn 1 in eqn 2

13 – x – x = 5

13 – 2x = 5

2x = 8

x = 4

Therefore, y = 13 – 4 = 9

The two-digit number = 10x + y = (10 * 4) + 9 = 49

Answer 2

Here is your solution

Given :-
The sum of two digit number is 13 .
if the number is subtracted from the one obtained by interchanging the digits the results is 45 .

Let
The two digits be x and y.

Number is 10x + y 

x + y = 13 (given)

y = 13 – x --------------1

A/q

10y + x – (10x + y) = 45

9y – 9x = 45

y – x = 5 --------------2

putting the value of y from equation 1 in eqn 2

13 – x – x = 5

13 – 2x = 5

2x = 8

x = 4✔

y = 13 – 4 = 9✔

The two-digit number = 10x + y = (10 × 4) + 9 = 49.

Hope it helps you.