Applicare la formula: $\frac{a}{b}+c$$=\frac{a+cb}{b}$, dove $a/b+c=\frac{1}{2}-1\times 10^{-3}$, $a=1$, $b=2$, $c=-\frac{1}{1000}$ e $a/b=\frac{1}{2}$

Applicare la formula: $ab$$=ab$, dove $ab=-\times 10^{-3}\cdot 2$, $a=-\frac{1}{1000}$ e $b=2$

Applicare la formula: $a+b$$=a+b$, dove $a=1$, $b=-\frac{1}{500}$ e $a+b=1-2\times 10^{-3}$

Applicare la formula: $\frac{a}{b}$$=\frac{a}{b}$, dove $a=0.998$, $b=2$ e $a/b=\frac{0.998}{2}$