x-(-8)-[x+(-8)] =

x + 8 – x + 8 =

0+16 =

16

= 16

x+8-[x(-8)].

Since the other equation is in brackets, you must multiply the equation by what is in front of it, which in this case is a 1. So you multiply 1 times x, and times -8, and you have x+8-x(-8). You have a positive x, and also a negative x, so they cancel out, leaving you with 8-(-8), and since two negatives are a plus, you have 16.

x+8-x+8

=16

I revised this. The ‘0’ I first had was way off. 16 is the correct answer.

x-(-8) is also x + 8 since according to the subtracting the negative sign rule, we shall chance the minus sign to + and change negative to positive

x + (-8) is equal to x – 8

so

x + 8 – x – 8

(x – x) + (8 – 8)

0 + 0

=0