\[Страница\ 28\]
\[\boxed{\mathbf{1.}}\]
\[12 - 7 = 5\]
\[9 + 8 = 17\]
\[11 - 3 = 8\]
\[5 + 6 = 11\]
\[11 - 4 = 7\]
\[16 - 7 = 9\]
\[18 - 9 = 9\]
\[15 - 6 = 9\]
\[84 - 80 = 4\]
\[37 - 7 = 30\]
\[42 - 40 = 2\]
\[59 - 9 = 50\]
\[\boxed{\mathbf{2.}}\]
\[Неверные\ неравенства\ \]
\[(верная\ запись).\]
\[15 - 8 < 15 - 7\]
\[7 + 5 = 5 + 7\]
\[16 - 0 = 16 + 0\]
\[\boxed{\mathbf{3.}}\]
\[90 - 30 + 6 = 66\]
\[40 + 20 + 10 = 70\]
\[80 - 50 + 9 = 39\]
\[30 + 60 + 7 = 97\]