(F)=6+3F
We move all terms to the left:
(F)-(6+3F)=0
We add all the numbers together, and all the variables
F-(3F+6)=0
We get rid of parentheses
F-3F-6=0
We add all the numbers together, and all the variables
-2F-6=0
We move all terms containing F to the left, all other terms to the right
-2F=6
F=6/-2
F=-3
I don’t know if it is right but I hope this helps :)