1. **State the problem:** We need to subtract the binary numbers $10111.1_2$ and $10011.1_2$. 2. **Recall binary subtraction rules:** - $0 - 0 = 0$ - $1 - 0 = 1$ - $1 - 1 = 0$ - $0 - 1$ requires borrowing from the next higher bit. 3. **Align the numbers:** $10111.1_2$ -$10011.1_2$ 4. **Subtract the fractional part:** $1 - 1 = 0$ 5. **Subtract the integer part from right to left:** - Units place: $1 - 1 = 0$ - Next bit: $1 - 1 = 0$ - Next bit: $1 - 0 = 1$ - Next bit: $0 - 0 = 0$ - Leftmost bit: $1 - 1 = 0$ 6. **Combine the results:** Integer part: $00100_2$ Fractional part: $0_2$ 7. **Simplify the integer part:** $00100_2 = 100_2$ 8. **Convert to decimal to verify:** $10111.1_2 = 23.5_{10}$ $10011.1_2 = 19.5_{10}$ $23.5 - 19.5 = 4_{10}$ $100_2 = 4_{10}$, which matches. **Final answer:** $100_2$