Rút gọn biểu thức

\(\frac{x-3\sqrt{x}}{\sqrt{x}-3}\times\frac{x+4\sqrt{x}+4}{\sqrt{x}+2}\)

Tính:

a/ \(\sqrt{8+2\sqrt{15}}+\frac{2}{\sqrt{5}+\sqrt{3}}\)

b/ \(\sqrt{7+2\sqrt{6}}+\frac{6-2\sqrt{6}}{\sqrt{6}}-\sqrt{54}\)

Tính giá trị

\(\frac{7}{\sqrt{3}-\sqrt{2}}-\sqrt{147}-2\sqrt{18}\)

I. Sửa lỗi sai :

1. Do you think (A - your) new bicycle (B - is) much (C - more cheaper) than (D - John's)?

2. The manager (A - is having) all the windows (B - on) the (C - second and third) floors as well as in the restaurent (D - replace)