Question

the sum of digit of a two digit number is 14. if 36 is added to the number it's digit are interchange find the number

Answer 1

x+y=14
10x+y+36=10y+x
9y-9x=36
y-x=4
y+x=14
add both eqns
2y=18
y=9,x=5
the number was
59

Answer 2

the no.=5 and 9...
{ x+y=14 n 10x+y+36=10y+x }