Zadanie 4
powtórzone: rozwiązanie zadania
Zadanie 5
\frac{(\frac{1}{5})^{-2}*(1\frac{2}{3})^{-1}-(3^{-1}-2^{-1})^{-2}}{(\frac{2}{21})^{-1}}=
\frac{5^2*(\frac{5}{3})^{-1}-(\frac{1}{3}-\frac{1}{2})^{-2}}{\frac{21}{2}}=
\frac{25*\frac{3}{5}-(\frac{2-3}{6})^{-2}}{\frac{21}{2}}=
\frac{15-(\frac{-1}{6})^{-2}}{\frac{21}{2}}=
\frac{15-(\frac{6}{-1})^{2}}{\frac{21}{2}}=
\frac{15-(-6)^{2}}{\frac{21}{2}}=
\frac{15-36}{\frac{21}{2}}=-21*\frac{2}{21}=-2