Question 473650
find the smallest number so that if 2 is added to twice the number,
its digits are reversed.
:
Let x = the original no. 10's digit
Let y = the units
:
The equation:
2(10x+y) + 2 = 10y + x
20x + 2y + 2 = 10y + x
20x - x + 2 = 10y - 2y 
19x + 2 = 8y
y = {{{19/8}}}x + {{{2/8}}}
y = {{{19/8}}}x + {{{1/4}}}
substitute single digit values for x, starting with 1, you can see that x=2 gives an integer value of y = 5
:
The original number is 25, and it checks out 2(25) + 2 = 52