Răspuns:
Explicație pas cu pas:
Exercitiul 13
[tex]a) (-\frac{4}{3})*(-\frac{5}{8}+\frac{1}{4})=(-\frac{4}{3})*(\frac{-5+2}{8})= (-\frac{4}{3})*(-\frac{3}{8})=\frac{4}{8}=\frac{1}{2}[/tex]
[tex]b)\frac{37}{25}*(\frac{7}{5} -\frac{3}{20})= \frac{37}{25}*(\frac{28-3}{20})= \frac{37}{25}*\frac{25}{20}=\frac{37}{20}[/tex]
[tex]d) 0,75*(-\frac{7}{3} +\frac{5}{6} )=0,75*(\frac{-14+5}{6})=0,75*(-\frac{9}{6})=\frac{75}{100}* (-\frac{3}{2})=\frac{3}{4}*(-\frac{3}{2})=-\frac{9}{8}[/tex]
[tex]e) 2,25*(-\frac{1}{7} +\frac{1}{21} )= 2,25*(\frac{-3+1}{21})=\frac{225}{100}*(-\frac{2}{21})=\frac{9}{4}*(-\frac{2}{21})=-\frac{3}{14}[/tex]
Exercitiul 14
[tex]a)(+\frac{3}{5} )*(\frac{-10}{9})*(\frac{15}{-2} )=(-\frac{2}{3})*(\frac{15}{-2} )=5[/tex]
[tex]b)(-3\frac{1}{2})*\frac{4}{7} *(\frac{-1}{4} )=(-\frac{7}{2})*(-\frac{1}{7})=\frac{1}{2}[/tex]
[tex]d) (\frac{-5}{6} )*3\frac{4}{5} *(\frac{-30}{-19} )=(\frac{-5}{6} )*\frac{19}{5} *(\frac{-30}{-19} )=(-\frac{19}{6})*(\frac{-30}{-19} )=-5[/tex]
[tex]e)(-9\frac{1}{7})*\frac{42}{128}*(-\frac{3}{27})=(-\frac{64}{7})*\frac{42}{128}*(-\frac{1}{9})=(-\frac{6}{2})*(-\frac{1}{9})=(-3)*(-\frac{1}{9})=\frac{1}{3}[/tex]
