Oblicz: 2,7*2/9-1 i 2/5:1,4 / [2-(1,5)^2]*4/5

\frac{2,7*\frac{2}{9}-1\frac{2}{5}:1/4}{[2-(1,5)^(2)]*\frac{4}{5}}=\\ =\frac{0,6-1,4:1,4}{[2-2,25]*0,8}=\frac{0,6-1}{-0,25*0,8}=\frac{-0,4}{-0,2}=2\\ [/mat]

2,7*\frac{2}{9}-1=\frac{27}{10}*\frac{2}{9}-1=\frac{3}{5}-1=-\frac{2}{5} \frac{2}{5}:\frac{1,4}{[2-(1,5)^2]*\frac{4}{5}}=\frac{2}{5}:\frac{\frac{14}{10}}{[2-(\frac{3}{2})^2]*\frac{4}{5}}=\frac{2}{5}:\frac{\frac{7}{5}}{(2-\frac{9}{4})*\frac{4}{5}}=\frac{2}{5}:\frac{\frac{7}{5}}{-\frac{1}{4}*\frac{4}{5}}=\frac{2}{5}:\frac{\frac{7}{5}}{-\frac{1}{5}}=\frac{2}{5}:\frac{7}{5}*(-5)=\frac{2}{5}:(-7)=\frac{2}{5}*(-\frac{1}{7})=-\frac{2}{35}

w 1 równaniu w liczniku zamiast 1/4 ma być 1,4(pomułka pisarska)