Question

1.thực hiện phép tính

a.(0,125).(-3.7).(-2)\(^3\)

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

c.\(\sqrt{\frac{4}{81}}:\sqrt{\frac{25}{81}}-1^2_5\)

d.\(0,1.\sqrt{225}.\sqrt{\frac{1}{4}}\)

Answer 1

Bài 1:

a) Ta có: \(\left(0.125\right)\cdot\left(-3\cdot7\right)\cdot\left(-2\right)^3\)

\(=\frac{1}{8}\cdot\left(-21\right)\cdot\left(-8\right)\)

\(=\frac{1}{8}\cdot168\)

\(=21\)

b) Ta có: \(\sqrt{36}\cdot\sqrt{\frac{25}{16}}+\frac{1}{4}\)

\(=\sqrt{36\cdot\frac{25}{16}}+\frac{1}{4}\)

\(=\sqrt{\frac{225}{4}}+\frac{1}{4}\)

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

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

c) Ta có: \(\sqrt{\frac{4}{81}}:\sqrt{\frac{25}{81}}-1\frac{2}{5}\)

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

\(=\frac{2}{5}-\frac{7}{5}=-1\)

d) Ta có: \(0,1\cdot\sqrt{225}\cdot\sqrt{\frac{1}{4}}\)

\(=0,1\cdot15\cdot\frac{1}{2}=\frac{3}{4}\)