\[\boxed{\mathbf{1}\mathbf{.}}\]
\[26 - 12 = 26 - 10 - 2 =\]
\[= 16 - 2 = 14\]
\[35 - 11 = 35 - 10 - 1 =\]
\[= 25 - 1 = 24\]
\[48 - 13 = 48 - 10 - 3 =\]
\[= 38 - 3 = 35\]
\[46 - 21 = 46 - 20 - 1 =\]
\[= 26 - 1 = 25\]
\[54 - 22 = 54 - 20 - 2 =\]
\[= 34 - 2 = 32\]
\[62 - 31 = 62 - 30 - 1 =\]
\[= 32 - 1 = 31\]
\[75 - 32 = 75 - 30 - 2 =\]
\[= 45 - 2 = 43\]
\[86 - 41 = 86 - 40 - 1 =\]
\[= 46 - 1 = 45\]
\[93 - 52 = 93 - 50 - 2 =\]
\[= 43 - 2 = 41\]