§ Задание 18
\[\boxed{\mathbf{18.}}\]
\[30 + 4 = 34\]
\[30 - 4 = 26\]
\[50 - 7 = 43\]
\[50 + 7 = 57\]
\[60 + 12 = 72\]
\[60 - 12 = 48\]
\[70 - 28 = 42\]
\[70 + 28 = 98\]
\[\boxed{\mathbf{18.}}\]
\[30 + 4 = 34\]
\[30 - 4 = 26\]
\[50 - 7 = 43\]
\[50 + 7 = 57\]
\[60 + 12 = 72\]
\[60 - 12 = 48\]
\[70 - 28 = 42\]
\[70 + 28 = 98\]