Applicare la formula: $x,\:a,\:b$$=eval\left(x,a,b\right)$, dove $a=x=11$, $b=y=81$, $x=x+\frac{1}{8}\sqrt{y-1}$ e $x;a=x+\frac{1}{8}\sqrt{y-1},\:x=11,\:y=81$

Applicare la formula: $a+b$$=a+b$, dove $a=81$, $b=-1$ e $a+b=81-1$

Applicare la formula: $\frac{a}{b}c$$=\frac{ca}{b}$, dove $a=1$, $b=8$, $c=\sqrt{80}$, $a/b=\frac{1}{8}$ e $ca/b=\frac{1}{8}\sqrt{80}$

Applicare la formula: $1x$$=x$, dove $x=\sqrt{80}$