Question

the sum of the digits of two digit number is 9 if the digits are interchanged and the resulting number is 9 less than the original number​

Answer 1

Step-by-step explanation:

let the digits by x and ,y

$x + y = 9 \\ 10y + x = 10x + y - 9 \\ - 9x + 9y = - 9 \\ y - x = - 1$

solving we get y=4

x=5