Question 835814
let m = my present age
let s = son's present age
:
let a = my 10's digit
let b = my units digit
:
if the digits of my present age are reversed then i get the age of my son.
m = 10a+b
s = 10b+a
if 1 year ago my age was twice as that of my son.
m-1 = 2(s-1)
m - 1 = 2s - 2
m = 2s - 2 - 1
m = 2s - 1
Replace m with (10a+b), replace s with (10b+a)
10a + b = 2(10b+a) - 1
10a + b = 20b + 2a - 1
10a - 2a = 20b - b - 1
8a = 19b - 1
a = {{{19/8}}}b - {{{1/8}}}
Substitute for b, look for an integer solution for a
b = 3 is only single digit that works
a = {{{19/8}}}(3) - {{{1/8}}}
a = {{{57/8}}}b - {{{1/8}}}
a = {{{56/8}}}
a = 7
 my age = 73