Step-by-step explanation:
lets take the first number as x
if the second digit is 6 more than the first, we should take it as x+6
if they add up to 12,then:
x+x+6 = 12
2x = 12 -6
2x = 6
x = 6/2=3
if the 1st digit is 3, then the 2nd will be 6+3=9
so the 2 digit number is 39
