§ Задание 20
\[\boxed{\mathbf{20.}}\]
\[46 + 4 = 50 > 49\]
\[46 - 4 = 42 < 49\]
\[80 + 8 = 88 > 84\]
\[80 - 8 = 72 < 84\]
\[60 - 31 = 29 < 30\]
\[60 + 31 = 91 > 30\]
\[\boxed{\mathbf{20.}}\]
\[46 + 4 = 50 > 49\]
\[46 - 4 = 42 < 49\]
\[80 + 8 = 88 > 84\]
\[80 - 8 = 72 < 84\]
\[60 - 31 = 29 < 30\]
\[60 + 31 = 91 > 30\]