§ Задание 23
\[\boxed{\mathbf{23}\mathbf{.}}\]

\[\textbf{б)}\ 30 + (5 + 9) = 30 + 14 = 44\]
\[75 - (13 - 9) = 75 - 4 = 71\]
\[(19 + 0) + 70 = 19 + 70 = 89\]
\[\boxed{\mathbf{23}\mathbf{.}}\]

\[\textbf{б)}\ 30 + (5 + 9) = 30 + 14 = 44\]
\[75 - (13 - 9) = 75 - 4 = 71\]
\[(19 + 0) + 70 = 19 + 70 = 89\]