(C012.25)H - (10111001110.101)B =

Solution (concise):

Step 1 — Convert the binary operand to octal:

• Group binary integer part in threes from the radix point to the left: 10111001110 → 010 111 001 110

• Map each 3-bit group to an octal digit: 010 → 2, 111 → 7, 001 → 1, 110 → 6 → integer part 2716

• Group fractional bits to the right of the point in threes: .101 → .101 → 5 → fractional part .5

• Therefore (10111001110.101)₂ = (2716.5)₈

Step 2 — Perform the subtraction in the same base (octal):

• Convert the other number (the left operand) into octal if it is not already in octal. Align integer and fractional parts and subtract digit by digit using base-8 borrowing rules (borrow 1 = 8 in the next lower place).

• Apply fractional borrows if needed across the radix point, then proceed with integer-part subtraction with borrows.

• Carrying out these steps (using the converted value (2716.5)₈ for the binary operand) yields the result (135103.412)₈.

Check (optional):

• You can verify the result by converting the final octal result back to binary or to decimal and ensuring that left operand − (10111001110.101)₂ equals the same decimal value.