Turn these sentences into the passive voice.

1.They need to wash the carpet.

2. You need to learn English everyday.

3. Ann needs to clean the floor once a day.

Cho \(a,b,c\ge0\) thỏa mãn \(a+b+c=3\). Chứng minh:\(\sqrt{a^2+ab+b^2}+\sqrt{b^2+bc+c^2}+\sqrt{c^2+ca+a^2}\ge3\sqrt{3}\)

Tính: A = \(\frac{2-\sqrt{3}}{1+\sqrt{4+2\sqrt{3}}}+\frac{2+\sqrt{3}}{1-\sqrt{4-2\sqrt{3}}}\)