Question

Resolver as operações abaixo.


a) $\frac{1 - \frac{2}{3} + \frac{4}{5}}{-\frac{17}{15} } =$



b) $\frac{9}{10} . \frac{5}{3} + \frac{8}{3} - \frac{21}{15} =$



c) $(\frac{3}{4} + \frac{2}{3} - \frac{7}{2} ) : (- \frac{5}{12} ) =$



d) $\frac{7}{\frac{1}{2} +\frac{1}{5} }=$

Answer 1

Explicação passo-a-passo:

a) $\frac{1-\frac{2}{3}+\frac{4}{5}}{-\frac{17}{15}}$

   no numerador, o m.m.c. de 1, 3 e 5 é 15

   $\frac{\frac{15:1.1-15:3.2+15:5.4}{15}}{-\frac{17}{15}}$

   $\frac{\frac{17}{15}}{-\frac{17}{15}}=-1$

************************************************************************************

b) $\frac{9}{10}.\frac{5}{3}+\frac{8}{3}-\frac{21}{15}$

   simplificando 9 com 3 e 5 com 10, fica

   $\frac{9:3}{10:5}.\frac{5:5}{3:3}+\frac{8}{3}-\frac{21}{15}$

   $\frac{3}{2}.\frac{1}{1}+\frac{8}{3}-\frac{21}{15}$

   $\frac{3}{2}+\frac{8}{3}-\frac{21}{15}$

   m.m.c. de 2, 3 e 15 é 30

   $\frac{30:2.3+30:3.8-30:15.21}{30}$

   $\frac{45+80-42}{30}=\frac{83}{30}$

**********************************************************************************

c) $(\frac{3}{4}+\frac{2}{3}-\frac{7}{2}):(-\frac{5}{12})$

   m.m.c. de 4, 3 e 2 é 12

   $(\frac{12:4.3+12:3.2-12:2.7}{12}):(-\frac{5}{12}$

   $(\frac{9+8-42}{12}):(-\frac{5}{12})$

   $-\frac{25}{12}:(-\frac{5}{12})=-\frac{25}{12}.(-\frac{12}{5})$

   simplificando 25 com 5 e 12 com 12, fica

   $-\frac{5}{1}.(-\frac{1}{1})=-5.(-1)=5$

*********************************************************************************

d) $\frac{7}{\frac{1}{2}+\frac{1}{5}}$

   m.m.c. de 2 e 5 é 10

   $\frac{7}{\frac{10:2.1+10:5.1}{10} }$

   $\frac{7}{\frac{5+2}{10}}=\frac{7}{\frac{7}{10}}=7.\frac{10}{7}=10$