a)
\frac{a-b}{a*b}=20
obliczam a-b
a-b=\frac{\sqrt3-2}{5}-\frac{\sqrt3+2}{5}=\frac{\sqrt3-2-\sqrt3-2}{5}=-\frac{4}{5}
obliczam a*b
a*b=\frac{\sqrt3-2}{5}*\frac{\sqrt3+2}{5}=\frac{3-4}{25}=-\frac{1}{25}
\frac{a-b}{a*b}=\frac{-\frac{4}{5}}{-\frac{1}{25}}=\frac{4}{5}*\frac{25}{1}=20 c.n.u
b)
|\frac{a}{b}|=|\frac{\sqrt3-2}{5}*\frac{5}{\sqrt3+2}|=
=|\frac{\sqrt3-2}{\sqrt3+2}*\frac{\sqrt3-2}{\sqrt3-2}|=
=|\frac{3-2\sqrt3-2\sqrt3+4}{3-4}|=
=|\frac{7-4\sqrt3}{-1}|=|4\sqrt3-7|=-(4\sqrt3-7)=7-4\sqrt3