Odpowiedź:
[tex] \frac{2}{3} \times 2.1 + 2 \times (3 \frac{2}{5} + 1.4) = \: \frac{2}{3} \times \frac{21}{10} + 2 \times 4.8 = \: \frac{21}{15} + \frac{48}{10} = \: \frac{42}{30} + \frac{144}{30} = \frac{186}{30} = 6 \frac{6}{30} = 6 \frac{1}{5} [/tex]
[tex](0.4 \times \frac{5}{3} - \frac{2}{9} ) \div 0.25 = \frac{4}{10} \times \frac{5}{3} - \frac{2}{9} \div 0.25 = \: \frac{2}{3} - \frac{2}{9} \div \frac{1}{4} = \frac{4}{9} \times \frac{4}{1} = \frac{16}{9} = 1 \frac{7}{9} [/tex]
[tex](1.2 + \frac{1}{25} ) \div 0.4 - (1.75 - \frac{5}{4} ) \times \frac{2}{3} = 1.24 \div 0.4 - 0.5 \times \frac{2}{3} = 3.1 - \frac{2}{6} = \frac{31}{10} - \frac{2}{6} = \frac{186}{60} - \frac{20}{60} = \frac{166}{60} = 8 \frac{1}{10} [/tex]
[tex] \frac{1}{8} \div 0.3 - (1.75 - \frac{1}{12} ) \times 0.25 = \frac{1}{8} \times \frac{10}{3} - ( \frac{175}{100} - \frac{1}{12} ) \times \frac{1}{4} = \frac{10}{24} - ( \frac{1050}{600} - \frac{50}{600} ) \times \frac{1}{4} = \frac{10}{24} - ( \frac{10}{6} \times \frac{1}{4} ) = \frac{10}{24} - \frac{10}{24} = 0[/tex]
proszę o naj :)
