Question

* Thực hiện phép tính

a. \(\sqrt{\left(3-\sqrt{2}\right)^2}+\sqrt{\left(2\left(-5\right)\right)^2}\)

b. \(\dfrac{\sqrt{270}}{\sqrt{30}}-\sqrt{1,8}.\sqrt{20}\)

Answer 1

a, \(\sqrt{\left(3-\sqrt{2}\right)^2}+\sqrt{\left(2\left(-5\right)\right)^2}\)

\(=\left|3-\sqrt{2}\right|+\sqrt{\left(-10\right)^2}\)

\(=3-\sqrt{2}+\left|-10\right|\)

\(=3-\sqrt{2}+10\)

\(=13-\sqrt{2}\)

b, \(\dfrac{\sqrt{270}}{\sqrt{30}}-\sqrt{1,8}.\sqrt{20}\)

\(=\sqrt{9}-\sqrt{1,8.20}\)

\(=3-\sqrt{36}\)

\(=3-6\)

\(=-3\)