2's complement additions(is my working correct)

Hi everyone

Need help to verify my working,especially for Qiii, the extra 9th bit is not present.

Perform the arithmetic using 2’s complement notation. The numbers are given in decimal, so first convert them to appropriate form. Make suitable assumptions.

(i) -29 – 37

-29 =00011101

nvert = 11100010+1

= 11100011

-37 =00100101

invert = 11011010+1

= 11011011

11100011+11011011=110111110

=-66

(ii) 95 – 28

95=01011111

-28=00011100

INVERT=11100011+1=11100100

01011111+11100100=01000011

=67

(iii) 28 – 78

28=00011100

-78=01001110=10110001+1=10110010

00011100+10110010=11001110

-50

Thank you for all your kind help & support.