39=-2(21-b)+3(b-3)

Solution for 39=-2(21-b)+3(b-3) equation:

39=-2(21-b)+3(b-3)

We move all terms to the left:

39-(-2(21-b)+3(b-3))=0

We add all the numbers together, and all the variables

-(-2(-1b+21)+3(b-3))+39=0


We calculate terms in parentheses: -(-2(-1b+21)+3(b-3)), so:

-2(-1b+21)+3(b-3)

We multiply parentheses

2b+3b-42-9

We add all the numbers together, and all the variables

5b-51

Back to the equation:

-(5b-51)


We get rid of parentheses

-5b+51+39=0

We add all the numbers together, and all the variables

-5b+90=0

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

-5b=-90

b=-90/-5

b=+18