To perform binary subtraction, we subtract column by column from right to left, borrowing 1 from the next higher place value when necessary (where $10_2 - 1_2 = 1_2$). (i) $(10000.11100)_2 - (101.01001)_2$ $$ \begin{aligned} \begin{array}{r@{\quad}l} & 10000.11100 \\ - & 00101.01001 \\ \hline & 01011.10011 \end{array} \end{aligned} $$ Result: $(1011.10011)_2$ (ii) $(1000001)_2 - (11111)_2$ $$ \begin{aligned} \begin{array}{r@{\quad}l} & 1000001 \\ - & 0011111 \\ \hline & 0100010 \end{array} \end{aligned} $$ Result: $(100010)_2$