You have to add 86 and 86 then you add 84 which will give you 156 then you subtract 84 to get 72 so for 1 is 72 for 4 is 86 + 84 to get 170 then subtract 86 to get 84 for for 3 is 86 + 86 add that to get 172 then subtract 86 to get 86 so for 1 is 72 for 3 is 86 and for 4 is 82