Question

the sum of the digitsof a 2 digits number is 12 of the new number reversing the digits greater than the original number 18 . find the original number​

Answer 1

Step-by-step explanation:

Let x be the unit digit and y be tens digit.

Then the original number be 10x+y.

Value of the number with reversed digits is 10y+x.

As per question, we have

x+y=12 ....(1)

If the digits are reversed, the digits is greater than the original number by 18.

Therefore, 10y+x=10x+y+18

⇒9x−9y=−18 ....(2)

Multiply equation (1) by 9, we get

9x+9y=108 ....(3)

Add equations (2)and (3),

18x=90

⇒x=5

Substitute this value in equation (1), we get

5+y=12⇒y=7

Therefore, the original number is 10x+y=10×5+7=57..

Answer 2

let the 2 digits be x and y

No.=10x+y

x+y=12

x=12-y.....(1)

10y+x=10x+y+18

9y-9x=18

y-x=2

y-(12-y)=2 (from (1))

y-12+y=2

2y=14

y=7

x=12-7

x=5

no.=57

reverse=75

difference=75-57=18