Question

The sum of the digits of a two-digit number is 9. If the number is subtracted from 45, then your values ​​are reversed, then find the number.​

Answer 1

Answer:

Let the ones digit be x

the tens digit be y

then no. is 10y+x

x+y =9

x=9-y

10y+x-45=10x+y

10y-y-45=10x-x

9y-45=9x

9(y-5)=9x

y-5=x

put the value of x

y-5=9-y

y+y =9+5

2y=14

y=7

x=9-y

x=9-7

x=2

so, the no. is=10*7+2

72

Answer 2

Answer:

a+b=9 .....(1)

a-b=45.....(2)

adding (1)&(2)

2a=54

a=27

put a=27 in equan 1

27+b=9

b=9-27

b=-18