Final answer:
The two's complement binary representation of -42 is 11010110 when using an 8-bit number format. This is obtained by converting 42 to binary, inverting the digits, and then adding 1 to the result.
Step-by-step explanation:
To find the two's complement binary number representation of -42 using 8-bit numbers, follow these steps:
- Convert the absolute value of the number to binary - 42 in decimal is 00101010 in binary.
- Invert the digits (0s become 1s and vice versa) to get the complement - the inverted number of 00101010 is 11010101.
- Add 1 to the inverted number to obtain the two's complement - adding 1 to 11010101 results in 11010110.
Therefore, the two's complement binary representation of -42 as an 8-bit number is 11010110.