Question

The sum of the digits of a two digit numben is 13.
if 9 is added to the number, the digits are
reversed. Find the orginal number.​

Answer 1

Answer:

67

Step-by-step explanation:

let the digits be x and y

x+y=13----(1)

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

10x+y-10y+9=x

10x-x-9y+9=0

9x-9y=-9

x-y=-1 ----(2)

(1)+(2):

2x=12

x=6

y=13-6 = 7

X is 6 and Y is 7

Answer 2

Answer:

$x + y = 13......(i)$

$x + y + 9 = 31$

$x = 31 - 9 - y.......(i)$

$y = 31 - 9 - x$

$x(10) + y$

$= (y - 22)10 = x0$

$10y - 220 + - x - 22$

$xy= 10y - 242 - x$

so x =6

y=7