Question

Thực hiện phép tính

\(\left(\sqrt{20}+\sqrt{3}-\sqrt{5}\right)\left(\sqrt{5}-\frac{1}{2}\sqrt{12}\right)\)

Answer 1

https://i.imgur.com/5kxhxcs.jpg

Answer 2

\(\left(\sqrt{20}+\sqrt{3}-\sqrt{5}\right)\left(\sqrt{5}-\frac{1}{2}\sqrt{12}\right)\)

=\(\left(2\sqrt{5}+\sqrt{3}-\sqrt{5}\right)\left(\sqrt{5}-\frac{1}{2}.2\sqrt{3}\right)\)

=\(\left(\sqrt{5}+\sqrt{3}\right)\left(\sqrt{5}-\sqrt{3}\right)\)

=\(5-3\)

=2

Answer 3

\(\left(\sqrt{20}+\sqrt{3}-\sqrt{5}\right)\left(\sqrt{5}-\frac{1}{2}\sqrt{12}\right)\)

=\(\left(\sqrt{5}-3\right)\left(\sqrt{5}-\frac{1}{2}.2.\sqrt{3}\right)\)

= \(\left(\sqrt{5}+3\right)\left(\sqrt{5}-3\right)\)

=5-9

=\(-4\)

Answer 4

https://i.imgur.com/TrG0ety.jpg