Q. A number of two digits has the sum of its digits as 7. When 9 is subtracted from the number, digits are reversed. The number is Question Q. A number of two digits has the sum of its digits as 7. When 9 is subtracted from the number, digits are reversed. The number is in progress 0 Math Valentina 2 months 2021-08-13T00:21:04+00:00 2021-08-13T00:21:04+00:00 1 Answer 0 views 0

## Answers ( )

EXPLANATION.GIVENa number of two digit has the sum of its digit

as = 7

when 9 is subtracted from the number, digit

are reversed.

TOFINDTHENUMBER.## According to the question,

Let the tens place = x

Let the unit place = y

original number = 10x + y

reversing number = 10y + x

## Conditions = 1

A number of two digit has the sum of its

digit = 7

=> x + y = 7 ……..(1)

## Conditions = 2

when 9 us subtracted from the number, digit

are reversed.

=> 10x + y – 9 = 10y + x

=> 9x – 9y = 9

=> x – y = 1 ……..(2)

From equation (1) and (2) we get,

=> 2x = 8

=> x = 4

put the value of x = 4 in equation (1)

we get,

=> 4 + y = 7

=> y = 3

## Therefore,

## Number are = 10x + y

## => 10(4) + 3 = 43

## Number are = 43