![(2)/(3)b+5=20-b](https://img.qammunity.org/2023/formulas/mathematics/college/rv025siup6kcp2impsij3pxvzh6kcelnda.png)
start by bringing all b's to one side of the equation and all constants to the other
![(2)/(3)b+b=20-5](https://img.qammunity.org/2023/formulas/mathematics/college/qgfj5qfk7d8s8o01f6wfems55tfdayv67u.png)
simplify both sides, remembering that 1 can be written as 3/3
![(2)/(3)b+(3)/(3)b=20-5](https://img.qammunity.org/2023/formulas/mathematics/college/v7jofvcaxraqu07nhz5484jn9wpisyore3.png)
since the fractions have the same denominator, we mantain the denominator and add the numerator together
![(5)/(3)b=15](https://img.qammunity.org/2023/formulas/mathematics/college/xdgj2ifhl40fcqvekixxhf6wtyodrmmem8.png)
multiply both sides by 3
![\begin{gathered} (3\cdot5)/(3)b=15\cdot3 \\ 5b=45 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/qp1yhrn0afv5ujdw9qy1vm7543dt16282z.png)
divide both sides by 5
![\begin{gathered} (5)/(5)b=(45)/(5) \\ b=9 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/zx5qnvs95ey2axv9upbm23ovrrq7q9mnj8.png)