Question

answer 4th question in photo

Answer 1

according to question

the sum of the digits is 15

x + y =15..........................(2)

next condition is the interchanging number is exceeds the orginal number is 9

the interchanging number = 10y +x

the orginal number = 10x + y

now condition

10y + x = 10x + y +9

10y -y -10x +x =9

9y -9x = 9

y - x =1 ..................(1)

now solve it

y - x =1

x +y =15

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2y =16

y =8

now sub in (1)

8 -x =1

x = 7