21=6+(2f+7)

Solution for 21=6+(2f+7) equation:

21=6+(2f+7)

We move all terms to the left:

21-(6+(2f+7))=0


We calculate terms in parentheses: -(6+(2f+7)), so:

6+(2f+7)

determiningTheFunctionDomain
(2f+7)+6

We get rid of parentheses

2f+7+6

We add all the numbers together, and all the variables

2f+13

Back to the equation:

-(2f+13)


We get rid of parentheses

-2f-13+21=0

We add all the numbers together, and all the variables

-2f+8=0

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

-2f=-8

f=-8/-2

f=+4