$(5$points $)$Use algebraic manipulation to find the minimum expression

$f(x,x,x)=A*B+A*C+B*C$

$(10$points$)$Perform the following operations involving eight$-$bit $2\text{'}$s complement

$A=115,B=-24,$ Get the result $of(A+B{)}_{2^{\text{'}}s}(A-B{)}_{2^{\text{'}}s}$

$5.(10$points$)$Perform the following operations involving eight$-$bit $2^{\text{'}}s$ complement numbers and indicate whether arithmetic overflow occurs. Check your answers by converting to decimal signand$-$magnitude representation.

$00110110,01110101,11011111$

$+01000101,+11011110,+10111000$