Question

Câu 1 : Thực hiện các phép tính:

   a)  \(\frac{-1}{4}\)  + \(\frac{3}{7}\)  + \(\frac{5}{4}\)  + \(\frac{-10}{7}\)            b) \(\frac{-7}{25}\) . \(\frac{11}{13}\) + \(\frac{-7}{25}\) . \(\frac{2}{13}\) - \(\frac{18}{25}\)          c) 2\(\frac{1}{5}\) + 20% - 0,2

Answer 1

\(b,\frac{-7}{25}.\frac{11}{13}+\frac{-7}{25}.\frac{2}{13}-\frac{18}{25}\)

\(=\frac{-7}{25}.\left(\frac{11}{13}+\frac{2}{13}\right)-\frac{18}{25}\)

\(=\frac{-7}{25}.1-\frac{18}{25}\)

\(=\frac{-7}{25}-\frac{18}{25}\)

\(=-1\)

Answer 2

a) \(\frac{-1}{4}+\frac{3}{7}+\frac{5}{4}+\frac{-10}{7}\)

\(=\left(\frac{-1}{4}+\frac{5}{4}\right)+\left(\frac{3}{7}+\frac{-10}{7}\right)\)

\(=\frac{4}{4}+\frac{-7}{7}\)

\(=1+-1\)

\(=0\)

Answer 3

a)\(=\left(-\frac{1}{4}+\frac{5}{4}\right)+\left(-\frac{10}{7}+\frac{3}{7}\right)\)

\(=1+\left(-1\right)\)

=0

b)\(=-\frac{7}{25}\left(\frac{11}{13}+\frac{2}{13}\right)-\frac{18}{25}\)

\(=-\frac{7}{25}.1-\frac{18}{25}\)

\(=-\frac{25}{25}\)

=-1

c)\(=\frac{11}{5}+0,2-0,2\)

\(=\frac{11}{5}+0\)

\(=\frac{11}{5}\)

Answer 4

\(c,2\frac{1}{5}+20\%-0,2\)

\(=\frac{11}{5}+\frac{1}{5}-\frac{1}{5}\)

\(=\frac{11}{5}\)

Answer 5

b) \(=-\frac{7}{25}\left(\frac{11}{13}+\frac{2}{13}\right)-\frac{18}{25}\)

\(=-\frac{7}{25}.1-\frac{18}{25}\)

\(=-\frac{7}{25}-\frac{18}{25}\)

\(=-\frac{25}{25}\)