Предмет: Математика, автор: Sonya541827264739

Помагите решить срочно
1)(4 1/2 -0,7)(1,85+3/20)=
2)(2,6+1 2/5)(4-2 4/25)=
3)(7 2/5+6,4):(5,2-29/10)=
4)(14-2 3/10):(3/5+0,7)=
Заранее спасибо

Ответы

Автор ответа: bbbapho

$(4 \frac{1}{2} - 0.7) \times (1.85 + \frac{3}{20} ) = (\frac{7}{2} - \frac{7}{10} ) \times ( \frac{185}{100} + \frac{3}{20} ) = (\frac{35}{10} - \frac{7}{10} ) \times ( \frac{185}{100} + \frac{15}{100} ) = \frac{28}{10} \times \frac{200}{100} = 2.8 \times 2 = 5.6$

$(2.6 + 1 \frac{2}{5} ) \times (4 - 2 \frac{4}{25} ) = ( \frac{26}{10} + \frac{7}{5} ) \times (4 - \frac{54}{25} ) = ( \frac{26}{10} + \frac{14}{10} ) \times (4 - \frac{216}{100} ) = \frac{40}{10} \times \frac{184}{100} = 4 \times 1.84 = 7.36$

$(7 \frac{2}{5} + 6.4) \div (5.2 - \frac{29}{10} ) = ( \frac{37}{5} + \frac{64}{10} ) \div ( \frac{52}{10} - \frac{29}{10} ) = ( \frac{74}{10} + \frac{64}{10} ) \div \frac{23}{10} = \frac{138}{10} \div \frac{23}{10} = \frac{138}{10} \times \frac{10}{23} = \frac{138}{23} = 6$

$(14 - 2 \frac{3}{10} ) \div ( \frac{3}{5} + 0.7) = (14 - \frac{23}{10} ) \div ( \frac{3}{5} + \frac{7}{10} ) = ( \frac{140}{10} - \frac{23}{10} ) \div ( \frac{6}{10} + \frac{7}{10} ) = \frac{117}{10} \div \frac{13}{10} = \frac{117}{10} \times \frac{10}{13} = \frac{117}{13} = 9$