A certain number is three times the sum of its digits,if 45 is added to the digit it is reverse. Find the digit.

Question

Let the two digit number be xy(10x and y)
xy=3(10x+y)
3(10x+y)+45=10y+x
how to solve this sum in addition and subtraction method
i don't know from here

Answer 1

if the digits are x and y, the value is 10x+y

10x+y = 3(x+y)
10x+y+45 = 10y+x

The number is thus 27

check:
27 = 3*(2+7)
27+45=72