Question

Thực hiện phép tính (bằng cách hợp lý nếu có thể):

a) \(\frac{2}{3}\)+ \(\frac{1}{3}\). \(\frac{6}{5}\)- 0,4

b) 3: \(\left(\frac{-3}{2}\right)^2\)+ \(\frac{1}{3}\). \(\sqrt{25}\)

c) 4\(\frac{2}{5}\) + \(\frac{5}{21}\)+ 1,5 - \(\frac{2}{25}\) + \(\frac{16}{21}\)

Giup mình với mình đang cần gấp, cảm ơn mn trước

Answer 1

\(a,\frac{2}{3}+\frac{1}{3}.\frac{6}{5}-0,4\)

=> \(\frac{2}{3}+\frac{2}{5}-\frac{2}{5}=>\frac{2}{3}+\left(\frac{2}{5}-\frac{2}{5}\right)\)

=> \(\frac{2}{3}+0=\frac{2}{3}\)

b, 3:\(\left(\frac{-3}{2}\right)^2\) + \(\frac{1}{3}.\sqrt{25}\)

=> \(3:\frac{9}{4}+\frac{1}{3}.5\)

=> \(\frac{4}{27}+\frac{5}{3}\)

=> \(\frac{12}{81}+\frac{135}{81}=\frac{147}{81}\)

c, \(4\frac{2}{5}+\frac{5}{21}+1,5-\frac{2}{25}+\frac{16}{21}\)

=> \(\left(\frac{22}{5}-\frac{2}{25}\right)+\left(\frac{5}{21}+\frac{6}{21}\right)+\frac{3}{2}\)

=> \(\frac{108}{25}+1+\frac{3}{2}\)

=> \(\frac{216}{50}+\frac{50}{50}+\frac{75}{50}\)

=> \(\frac{341}{50}\)

Answer 2

a, \(\frac{2}{3}\) + \(\frac{1}{3}\) . \(\frac{6}{5}\) - 0,4

= \(\frac{2}{3}\) + \(\frac{2}{5}\) - \(\frac{2}{5}\)

= \(\frac{2}{3}\)

b, 3 : (\(\frac{-3}{2}\) )² + \(\frac{1}{3}\) . \(\sqrt{25}\)

= 3 : \(\frac{9}{4}\) + \(\frac{1}{3}\) . 5

= 3 . \(\frac{4}{9}\) + \(\frac{5}{3}\)

= \(\frac{4}{3}\) + \(\frac{5}{3}\)

= 1

c, 4\(\frac{2}{5}\) + \(\frac{5}{21}\) + 1,5 - \(\frac{2}{25}\) + \(\frac{16}{21}\)

= \(\frac{22}{5}\) + \(\frac{5}{21}\) + \(\frac{3}{2}\) - \(\frac{2}{25}\) + \(\frac{16}{21}\)

= \(\frac{341}{50}\)

Answer 3

a) \(\frac{2}{3}+\frac{1}{3}.\frac{6}{5}-0,4\)

= \(\frac{2}{3}+\frac{2}{5}-\frac{2}{5}\)

=\(\frac{2}{3}\)

b) \(3:\left(\frac{-3}{2}\right)^2+\frac{1}{3}.\sqrt{25}\)

=\(3:\frac{9}{4}+\frac{1}{3}.5\)

=\(3.\frac{4}{9}+\frac{5}{3}\)

=\(\frac{4}{3}+\frac{5}{3}\)

=\(\frac{9}{3}\)

= 3

c) \(4\frac{3}{5}+\frac{5}{21}+1,5-\frac{2}{25}+\frac{16}{21}\)

=\(\frac{23}{5}+\frac{5}{21}+\frac{3}{2}-\frac{2}{25}+\frac{16}{21}\)

=\(\left(\frac{23}{5}-\frac{2}{25}\right)+\left(\frac{5}{21}+\frac{16}{21}\right)+\frac{3}{2}\)

=\(\left(\frac{115}{25}-\frac{2}{25}\right)+1+\frac{3}{2}\)

=\(\frac{113}{25}+1+\frac{3}{2}\)

=\(\frac{230}{50}+\frac{50}{50}+\frac{75}{50}\)

=\(\frac{355}{50}=\frac{71}{10}\)

Chúc bn học tốt !