Question

Please solve this question

Answer 1

Answer:

16

Step-by-step explanation:

Let the number be of form xy,

=> the number xy = 10x + y (Basic arithmetic operation on numbers)

Now, According to the question :

x + y = 7

And xy + 45 = yx

=> 10x + y + 45 = 10y + x

=> 9x + 45 = 9y

=>x + 5 = y (Divided by 9 on both sides)

Now solving the 2 linear equation we have,

x + y = 7

x + 5 = y

=> y - 5 = 7 - y (Subtracting above 2 equations)

=> 2y = 12 (Divide 2 on both sides)

=> y = 6

=> Substituting y in anyone of the above equation yields x

=> x = 6 - 5 = 1

=> The number is 16

Why?

Sum of digits of 16 = 1+6 = 7

16 + 45 = 61 => Digits reversed.

Therefore the answer to your question is 16.

Hope you understand, Any query? Comment down below.

Have a great day ,Thanking you,

Bunti 360 !

Answer 2

Answer:

Step-by-step explanation:

let the unit digit of the original no. x ,then tenth digit will be tenth(7-x) or 10(7-x) or 70-10x. so the no. will be 70-10x+x = 70-11x

after adding 45, the digits of the reversed no. will be >> unit place = (7-x)

                                                                   tenth place = tenth(x) = 10(x) = 10x

the reversed no. will be 10x + 7 - x =9x+7

................. u can find ur ans.