First we have divide them by a number which can be used to divide both at the same time. Since both numbers are divisible by 2, we are going to start with that number
18 36 l 2
9 18 l 3 After dividing by 2 we must divide by 3 because both are
divisible by 3
3 6 l 3 After dividing by 3 we must divide by 3 because both are
divisible by 3
1 2 l x We have to stop here because there is not any number different than 1 to divide these final two numbers
Finally we multiply our prime numbers ( used for dividing) and we find our GFC
which is 18
