Question

ex 252 ursor urgent 28puncte​

Answer 1

Răspuns:

$\frac{4}{15}$

Explicație pas cu pas:

$\frac{18}{25} *[(\frac{1}{7} +\frac{5}{42}*\frac{4}{5} )*\frac{14}{5} +\frac{1}{6}]-(1-\frac{3}{5} )*(\frac{2}{3} +\frac{3}{4} -\frac{7}{12} )=$

$=\frac{18}{25} *[(\frac{1}{7} +\frac{4}{42} )*\frac{14}{5} +\frac{1}{6}]-(\frac{5}{5} -\frac{3}{5} )*(\frac{8}{12} +\frac{9}{12} -\frac{7}{12} )=$

$=\frac{18}{25} *[(\frac{3}{21} +\frac{2}{21} )*\frac{14}{5} +\frac{1}{6}]-\frac{2}{5}*\frac{10}{12} =$

$=\frac{18}{25} *(\frac{5}{21} *\frac{14}{5} +\frac{1}{6})-2*\frac{2}{12} =$

$=\frac{18}{25} *(\frac{14}{21} +\frac{1}{6})-\frac{4}{12} =$

$=\frac{18}{25} *(\frac{2}{3} +\frac{1}{6})-\frac{1}{3} =$

$=\frac{18}{25} *(\frac{4}{6} +\frac{1}{6})-\frac{1}{3} =$

$=\frac{18}{25} *\frac{5}{6}-\frac{1}{3} = \frac{3}{5} -\frac{1}{3} =\frac{9}{15} -\frac{5}{15} =\frac{4}{15}$