Question

Giúp mình với mình cần gấp!

Answer 1

c) Ta có: \(\dfrac{5}{9}\cdot\dfrac{7}{13}-\dfrac{30}{23}+\dfrac{6}{9}\cdot\dfrac{5}{13}+\dfrac{7}{23}\)

\(=\dfrac{5}{13}\cdot\dfrac{7}{9}+\dfrac{6}{9}\cdot\dfrac{5}{13}-\dfrac{30}{23}+\dfrac{7}{23}\)

\(=\dfrac{5}{13}\left(\dfrac{7}{9}+\dfrac{6}{9}\right)-1\)

\(=\dfrac{5}{13}\cdot\dfrac{13}{9}-1\)

\(=\dfrac{-4}{9}\)

Answer 2

d) Ta có: \(\left(-3.2\right)\cdot\dfrac{-15}{64}+\left(0.8-2\dfrac{4}{5}\right):3\dfrac{2}{3}\)

\(=\dfrac{16}{5}\cdot\dfrac{15}{64}+\left(\dfrac{4}{5}-\dfrac{14}{5}\right):\dfrac{11}{3}\)

\(=\dfrac{3}{4}-2:\dfrac{11}{3}\)

\(=\dfrac{3}{4}-2\cdot\dfrac{3}{11}\)

\(=\dfrac{3}{4}-\dfrac{6}{11}=\dfrac{33}{44}-\dfrac{24}{44}=\dfrac{9}{44}\)

Answer 3

c) \(\dfrac{5}{9}.\dfrac{7}{13}-\dfrac{30}{23}+\dfrac{6}{9}.\dfrac{5}{13}+\dfrac{7}{23}\) 

=\(\dfrac{5}{9}.\dfrac{7}{13}-\dfrac{30}{23}+\dfrac{6}{13}.\dfrac{5}{9}+\dfrac{7}{23}\) 

=\(\dfrac{5}{9}.\left(\dfrac{7}{13}-\dfrac{6}{13}\right)+\left(\dfrac{-30}{23}+\dfrac{7}{23}\right)\) 

=\(\dfrac{5}{9}.\dfrac{1}{13}+\left(-1\right)\) 

=\(\dfrac{5}{117}+\left(-1\right)\) 

=\(\dfrac{-112}{117}\) 

d) \(\left(-3,2\right).\dfrac{-15}{64}+\left(0,8-2\dfrac{4}{5}\right):3\dfrac{2}{3}\) 

=\(\dfrac{-16}{5}.\dfrac{-15}{64}+\left(\dfrac{4}{5}-\dfrac{14}{5}\right):\dfrac{11}{3}\) 

=\(\dfrac{3}{4}+\left(-2\right):\dfrac{11}{3}\) 

=\(\dfrac{3}{4}+\left(\dfrac{-6}{11}\right)\) 

=\(\dfrac{9}{44}\)

Answer 4

c) \(\dfrac{5}{9}.\)\(\dfrac{7}{13}-\dfrac{30}{23}+\dfrac{6}{9}.\dfrac{5}{13}+\dfrac{7}{23}\)

=\(\left(\dfrac{5}{9}+\dfrac{6}{9}\right).\left(\dfrac{7}{13}+\dfrac{5}{13}\right)+\left(\dfrac{30}{23}-\dfrac{7}{23}\right)\)

=\(\dfrac{11}{9}.\dfrac{13}{13}+\dfrac{23}{23}\)

=\(\dfrac{11}{9}.1+1\)

=\(\dfrac{11}{9}+1\)

=\(\dfrac{11}{9}+\dfrac{1}{1}\)

=\(\dfrac{11}{9}+\dfrac{9}{9}\)

=\(\dfrac{20}{9}\)

Theo mình là thế nhé !~

Answer 5

Làm lại câu c:

c)\(\dfrac{5}{9}.\dfrac{7}{13}-\dfrac{30}{23}+\dfrac{6}{9}.\dfrac{5}{13}+\dfrac{7}{23}\) 

=\(\dfrac{5}{13}.\dfrac{7}{9}+\dfrac{6}{9}.\dfrac{5}{13}-\dfrac{30}{23}+\dfrac{7}{23}\) 

=\(\dfrac{5}{13}.\left(\dfrac{7}{9}+\dfrac{6}{9}\right)-1\) 

=\(\dfrac{5}{13}.\dfrac{13}{9}-1\) 

=\(\dfrac{5}{9}-1\) 

=\(\dfrac{-4}{9}\)

Answer 6

c)\(\frac{5}{9}.\frac{7}{13}-\frac{30}{23}+\frac{6}{9}.\frac{5}{13}+\frac{7}{23}=\)\(\frac{5}{9}.\frac{7}{13}-\frac{30}{23}+\frac{5}{9}.\frac{6}{13}+\frac{7}{23}\)

                                                                 =      \(\frac{5}{9}.\left(\frac{7}{13}+\frac{6}{13}\right)-\frac{30}{23}+\frac{7}{23}\)

                                                                 =      \(\frac{5}{9}.1-\frac{23}{23}\)

                                                                 =         \(\frac{5}{9}-1=-\frac{4}{9}\)