This is the basic and exam oriented question from linear equations in two variables in which we have to calculate the number if their sum of their digits is 10 and their digit gets reversed if 18 is subtracted from the number.

Kindly solve the above problem

RS Aggarwal, Class 10, chapter 3F, question no 10

Let one’s digit of a two number isÂ xÂ and ten’s digitsÂ y, then the number isÂ x+10y

By reversing its digits One’s digitÂ =yÂ and ten’s digitÂ =x

Then the number isÂ y+10x

As per statement

x+y=10...(1)

And,

x+10yâˆ’18=y+10x

x+10yâˆ’y10x=18

âˆ’9x+9y=18

xâˆ’y=âˆ’2Â (Dividing byÂ âˆ’9) ….(2)

AddingÂ (1)Â andÂ (2), we have

2x=8Â orÂ x=4

FromÂ (1):4+y=10

y=6

Answer:

NumberÂ =x+10y=4+10(6)=64