Posted by Joe Mhar Plaza on Thursday, January 6, 2011 at 10:10pm.
Assistance needed.
let the unit digit be x
let the tens digit be y
so the "value" of the two digit number is 10y + x
and then you said:
10y + x = 11y
x = y
but we also know x+y = 12
mmmh? Can you think of two numbers that are equal and add up to 12 without doing the algebra?