va rog dau 20 de pt daca este coarecta

Răspuns:

[tex](2 \frac{2}{5} - 1\frac{2}{5} - \frac{1}{6} ) \div( (0.2(3) \times \frac{10}{7} + \frac{1}{2} ) ^{2} = \\ = ( \frac{2 \times 5 + 2}{5} - \frac{1 \times 5 + 2}{5} - \frac{1}{6} ) \div ( \frac{23 - 2}{90} \times \frac{10}{7} + \frac{1}{2} ) ^{2} = \\ = ( \frac{12}{5} - \frac{7}{5} - \frac{1}{6} ) \div ( \frac{21}{90} \times \frac{10}{7} + \frac{1}{2} ) ^{2} = \\ = ( \frac{5}{5} - \frac{1}{6} ) \div ( \frac{3}{9} \times 1 + \frac{1}{2} ) ^{2} = \\ = (1 - \frac{1}{6} ) \div ( \frac{1}{3} + \frac{1}{2} ) ^{2} = \\ = ( \frac{6}{6} - \frac{1}{6} ) \div ( \frac{2}{6} + \frac{3}{6} ) ^{2} = \\ = \frac{5}{6} \div ( { \frac{5}{6} })^{2} = \\ = \frac{5}{6} \div \frac{ {5}^{2} }{ {6}^{2} } = \frac{5}{6} \div \frac{25}{36} = \\ = \frac{5}{6} \times \frac{36}{25} = 1 \times \frac{6}{5} = \frac{6}{5} [/tex]

[tex]\it \Big(2\dfrac{2}{5}-1\dfrac{2}{5}-\dfrac{1}{6}\Big):\Big[0,2(3)\cdot\dfrac{10}{7}+\dfrac{1}{2}\Big]^2=\Big(1-\dfrac{1}{6}\Big):\Big(\dfrac{21}{90}\cdot\dfrac{10}{7}+\dfrac{1}{2}\Big)^2=\\ \\ \\ =\dfrac{5}{6}:\Big(\dfrac{1}{3}+\dfrac{1}{2}\Big)^2=\dfrac{5}{6}:\Big(\dfrac{5}{6}\Big)^2=\dfrac{5}{6}\cdot\dfrac{36}{25}=\dfrac{^{2)}6}{\ 5}=\dfrac{12}{10}=1,2[/tex]