Question

a)\(\sqrt{\frac{4}{81}}\): \(\sqrt{\frac{25}{81}}\)- 1\(\frac{2}{5}\)

b) \(\sqrt{36}\). \(\sqrt{\frac{25}{16}}\)+ \(\frac{1}{4}\)

c) 1\(\frac{1}{2}\)+ \(\frac{4}{7}\): \(\frac{-8}{9}\)

d) 1,17 - 0,4.\(\frac{1}{2}\)^2 -\(\frac{1}{-5}\)

Answer 1

a) \(\sqrt{\frac{4}{81}}:\sqrt{\frac{25}{81}}-1\frac{2}{5}\)

\(=\frac{2}{9}:\frac{5}{9}-\frac{7}{5}\)

\(=\frac{2}{5}-\frac{7}{5}\)

\(=-1.\)

b) \(\sqrt{36}.\sqrt{\frac{25}{16}}+\frac{1}{4}\)

\(=6.\frac{5}{4}+\frac{1}{4}\)

\(=\frac{15}{2}+\frac{1}{4}\)

\(=\frac{31}{4}.\)

c) \(1\frac{1}{2}+\frac{4}{7}:\left(-\frac{8}{9}\right)\)

\(=\frac{3}{2}+\frac{4}{7}:\left(-\frac{8}{9}\right)\)

\(=\frac{3}{2}+\left(-\frac{9}{14}\right)\)

\(=\frac{6}{7}.\)

d) \(1,17-0,4.\left(\frac{1}{2}\right)^2-\frac{1}{-5}\)

\(=\frac{117}{100}-\frac{2}{5}.\frac{1}{4}-\left(-\frac{1}{5}\right)\)

\(=\frac{117}{100}-\frac{1}{10}+\frac{1}{5}\)

\(=\frac{107}{100}+\frac{1}{5}\)

\(=\frac{127}{100}.\)

Chúc bạn học tốt!

Answer 2

a, \(\frac{4}{81}:\sqrt{\frac{25}{81}-1\frac{2}{5}}\)

\(\Rightarrow\frac{4}{81}:\frac{5}{9}-\frac{7}{5}\)

\(\Rightarrow\frac{4}{81}.\frac{9}{5}-\frac{7}{5}\)

\(\Rightarrow\frac{4}{9}.\frac{1}{5}-\frac{7}{5}\)

\(\Rightarrow\frac{-59}{45}\)

b,\(\sqrt{36}.\sqrt{\frac{25}{16}+\frac{1}{4}}\)

\(\Rightarrow6.\frac{5}{4}+\frac{1}{4}\)

\(\Rightarrow\frac{15}{2}+\frac{1}{4}\)

\(\Rightarrow\frac{31}{4}\)

c,\(1\frac{1}{2}+\frac{4}{7}:\frac{-8}{9}\)

\(\Rightarrow\frac{3}{2}-\frac{4}{7}.\frac{-8}{9}\)

\(\Rightarrow\frac{3}{2}-\frac{9}{14}\)

\(\Rightarrow\frac{6}{7}\)

d, \(1,17-\left(0,4.\frac{1}{2}\right)^2-\frac{1}{5}\)

\(\Rightarrow\frac{117}{100}-\left(\frac{1}{5}\right)^2-\frac{1}{5}\)

\(\Rightarrow\frac{117}{100}-\frac{1}{25}-\frac{1}{5}\)

\(\Rightarrow\frac{93}{100}\)