Question

sum of two digit number is 15.if one s' place digit is y , then write the number.
frame the equation​

Answer 1

Explanation:

Let the units digit be x and tens digit be y.

Then, x+y=15 ……….(i)

Given number: 10y+x

Interchanged digits: 10x+y

A.t.Q:-

⇒(10x+y)−(10y+x)=9

⇒10x+y−10y−x=9

⇒9x−9y=9

⇒x−y=1 ………(ii)

Solving (i) and (ii)

x=8, y=7

∴ Two digit number=78

Answer 2

Answer:

sum of two digits = 15

ones place digit = y

let tens place digit = x

number = 10x + y

10x + y = 15