F (x) = 6x + 5

36x+35

(F) = 6F+536F+35

We move all terms to the left:

(F) - (6F+536F+35) = 0

We add all the numbers together, and all the variables

F - (542F+35) = 0

We get rid of parentheses

F-542F-35=0

We add all the numbers together, and all the variables

-541F-35=0

We move all terms containing F to the left, all other terms to the right

-541F=35

F=35/-541

F=-35/541