Applicare la formula: $\frac{a}{b}+c$$=\frac{a+cb}{b}$, dove $a/b+c=0.95-\frac{1}{4}$, $a=-1$, $b=4$, $c=\frac{19}{20}$ e $a/b=-\frac{1}{4}$

Applicare la formula: $ab$$=ab$, dove $ab=0.95\cdot 4$, $a=\frac{19}{20}$ e $b=4$

Applicare la formula: $a+b$$=a+b$, dove $a=\frac{19}{5}$, $b=-1$ e $a+b=-1+3.8$

Applicare la formula: $\frac{a}{b}$$=\frac{a}{b}$, dove $a=\frac{14}{5}$, $b=4$ e $a/b=\frac{2.8}{4}$