Question

the sum of two digits number is 15the number obtained by interchanging digits exceeds the given number by 9 find original number​

Answer 1

let the digit at tens place be x and one's place be y

original number =10x+y

according to question we have

x+y=15(1) equation

after interchanging the digit we have y at tens place and x at one's place

therefore

new no.=10y+x

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

10x+y-10y-x=9

9x-9y=9

x-y=1(2)equation

therefore equation 1 and 2

x+y=15

x-y=1

2x=16

x=8

from equation 1 and 2we have

x+y=15

1+y=15

y=14