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.

Answer 1

21 is the number when subtracted by 9 answers in 12.

Answer 2

Let the digit be xy

sum if two digit no=3

10x+y=3

9 subtracted from the no

10x+y-9=10y+x

=10x-x+y-10y=9

=9x-9y=9

=x-y=1

10x+y=3

x-y=1

(10x+y=3)×1

(x-y=1)×10

10x+3y=3

10x-10y=10

13y=(-7)

y={(-7/13)

x-y=1

x-(-7/13)=1

x+7/13=1

13x+7/13=1

13x+7=13

13x=6

x=6/13