Question

the sum of digit of a two digit number is seven dot on reversing its digit, then new number is 45 less than the original number find the number

Answer 1

hey mate!

here is your answer:

let the ten's digit of the number be x and one's digit be y

according to the question:

x+y=7

x=7-y......(1)

now, as the number is a 2 digit number it can be written as 10x+y

reversing the digit we get 10y+x

now, 10y+x=10x-y-45

10y-y=10x-x-45

9y=9x-45

9y-9x=-45.

9y-9(7-y)=-45 from (1)

9y-63+9y=-45

18y=-45+63

18y=18

y=18/18

y=1

and x =7-y

x=7-1=6

The number is 61

hope it helped you ^_^

Answer 2

Heya

GOOD MORNING

_______________________________

Let the two digit number be xy

xy can be written as 10x + y

ACCORDING TO THE QUESTION

x + y = 7 ... equation ( i )

=>

10y + x = 10x + y -45

=>

9y - 9x = -45

=>

y - x = -5 .... equation ii

Solve both equations we get

2y = 12

y = 6

And

x =1

So, the two digit number is 16