Question

the sum of a two digit number is 15 the original number is reversed. the reversed number is greater than original number by 9.find the numbet​

Answer 1

Answer:

Step-by-step explanation:

let the unit digit be x

           and ten's digit be y

therefore the number is 10y+x.

        if the number is reversed

then the new number is 10x+y

Since the reversed number is greater than original number by 9.

According to question:

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

10x + y - 10y - x =9

9x - 9y = 9

9 (x - y) = 9

 x - y = 9/9

x - y = 1 let it be equation 1

x + y = 15  let it be equation 2

by using elimination method

On adding equation 1 and 2

x - y = 1

x + y = 15

_________

2x = 16

x = 16/2

x = 8

Since both the y's were having opposite sign they got cancelled.

then

Substituting the value of x in equation 2

x + y = 15

then

8 + y = 15

y = 15 - 8

y = 7

therefore

to cross check

Substituting the value of x in equation 1

x - y = 1

8 -y = 1

8 - 1 = y

y = 7

therefore

x = 8

y = 7

then the number is

10y + x

(10 x 7) + 8

70 + 8

78

Hope I may have helped you.......