Evaluate the following expressions, in which each operand is an $8$ bit $2$s complement number,

using the standard binary addition algorithm $($evaluate subtraction by negating then adding$).$

As well as showing each result in $8$ bit two$$s complement, also convert and express each as

a signed decimal number. Note that whenever there is signed overflow your answer will not

be correct. For which expression$($s$)$ does this occur?

$($a$)00100110+01010111$

$1$

$($b$)11111111-01111111$

$($c$)10111010+11000010$

$($d$)10111110+11010111$