Question

Answer 1

Câu 1:
\(\sqrt{3}\in I\)
\(-\sqrt{5}\in R\)
\(\pi\in I\)
\(-1,99\notin Z\)
\(-90\%\in Q\)
\(2\in R\)
Câu 2:
\(a,\dfrac{-3}{5}:\dfrac{2}{3}-\dfrac{1}{2}.\dfrac{4}{7}\)
\(=\dfrac{-3}{5}.\dfrac{3}{2}-\dfrac{2}{7}\)
\(=\dfrac{-9}{10}-\dfrac{2}{7}\)
\(=\dfrac{-63}{70}-\dfrac{20}{70}\)
\(=\dfrac{-83}{70}\)
\(b,\dfrac{2}{3}+\left(-\dfrac{3}{2}\right).\left(-\dfrac{4}{10}\right)\)
\(=\dfrac{2}{3}+\dfrac{3}{5}\)
\(=\dfrac{10}{15}+\dfrac{9}{15}=\dfrac{19}{15}\)
\(c,\sqrt{\dfrac{4}{9}}.1,5-\left|\dfrac{-2}{5}\right|:\left(0,5-0,25\right)\)
\(=\dfrac{2}{3}.\dfrac{3}{2}-\dfrac{2}{5}:0,25\)
\(=1-\dfrac{2}{5}:\dfrac{1}{4}\)
\(=1-\dfrac{2}{5}.4\)
\(=1-\dfrac{8}{5}\)
\(=\dfrac{-3}{5}\)