7. Convert decimal +54, -54, -25, and +25 to binary using enough digits to accommodate the numbers. Then perform the binary equivalent of (+54)+ (+25), +54) +(-25), (-54)+ (+25), and (-54) + (-25). Convert then answers back to decimal and verify that they are correct. 8. Convert decimal 256 and 325 to BCD codes, and perform their addition using the BCD codes. 9. Convert the characters "8Ce3" to ASCII codes. Append an odd parity bit to eac at the left. 10. The following is a string of ASCII characters whose bit patterns have been converted into hexadecimal for compactness: 4A EF 68 6E 20 C4 EF E5. Of the 8 bits in each pair of digits, the leftmost is a parity bit. The remaining bits are the ASCII code. (a) Convert to bit form and decode the ASCI. (b) determine the parity used: odd or even