6 is outside the bracket, so u do 6 multiplied by 3m to give 18m. And then 6 multiplied by 5 to give 30 which equals 66
so 18m + 30 = 66
then u find out what m is by putting m on its own. So I subtract 30 from 30 and 66.
Ur left with : 18m= 36
then do 36 / 18 which equals to 2.
Therefore m = 2