$-\frac{ 1 }{ 2 }+\frac{ -1 }{ 2 }+\frac{ 1 }{ 2 }+\frac{ -1 }{ 2 }$
The sum of two opposites equals $0$$0+\frac{ -1 }{ 2 }+\frac{ -1 }{ 2 }$
Removing $0$ doesn't change the value, so remove it from the expression$\frac{ -1 }{ 2 }+\frac{ -1 }{ 2 }$
Write all numerators above the common denominator$\frac{ -1-1 }{ 2 }$
Calculate the difference$\frac{ -2 }{ 2 }$
Use $\frac{ -a }{ b }=\frac{ a }{ -b }=-\frac{ a }{ b }$ to rewrite the fraction$-\frac{ 2 }{ 2 }$
Any expression divided by itself equals $1$$-1$