3(b-21)=21-3(b-4)

Solution for 3(b-21)=21-3(b-4) equation:

3(b-21)=21-3(b-4)

We move all terms to the left:

3(b-21)-(21-3(b-4))=0

We multiply parentheses

3b-(21-3(b-4))-63=0


We calculate terms in parentheses: -(21-3(b-4)), so:

21-3(b-4)

determiningTheFunctionDomain
-3(b-4)+21

We multiply parentheses

-3b+12+21

We add all the numbers together, and all the variables

-3b+33

Back to the equation:

-(-3b+33)


We get rid of parentheses

3b+3b-33-63=0

We add all the numbers together, and all the variables

6b-96=0

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

6b=96

b=96/6

b=16