Question

Раскройте скобки и найдите значение выражения

Answer 1

$3.15+(\frac{2}{3} -2.15)=\frac{315}{100} +(\frac{2}{3} -\frac{215}{100})=\frac{63}{20} +(\frac{2}{3} -\frac{43}{20} )=\frac{63}{20} +(\frac{40}{60} -\frac{129}{60} )=\frac{63}{20} -\frac{89}{60} =\\\\=\frac{189}{60} -\frac{89}{60} =\frac{100}{60} =\frac{5}{3} =1\frac{2}{3} \\\\\frac{5}{12} -(\frac{1}{12} -\frac{2}{3} )=\frac{5}{12} -(\frac{1}{12} -\frac{8}{12} )=\frac{5}{12} +\frac{7}{12}=\frac{12}{12} =1$

$4\frac{5}{8} -(2\frac{3}{8} +1\frac{1}{4} )=\frac{37}{8} -(\frac{19}{8} +\frac{5}{4} )=\frac{37}{8} -(\frac{19}{8} +\frac{10}{8} )=\frac{37}{8} -\frac{29}{8} =\frac{8}{8} =1$