So sánh biểu thức C = \(\sqrt{x}-1\)(Đkxđ \(x\ge0;x\ne1\)) với \(\frac{-2}{x}\)

Cho x,y,z thoả mãn \(\sqrt{x}+\sqrt{y}+\sqrt{z}=7\); x+y+z=23 ; \(\sqrt{xyz}=3\). Tính giá trị biểu thức M =\(\frac{1}{\sqrt{xy}+\sqrt{z}-6}+\frac{1}{\sqrt{yz}+\sqrt{x}-6}+\frac{1}{\sqrt{zx}+\sqrt{y}-6}\)

Tìm các số nguyên x, y thoả mãn \(\frac{5}{x+y\sqrt{z}}-\frac{4}{x-y\sqrt{z}}+18\sqrt{2}=3\)

THỰC HIỆN PHÉP TÍNH \(\frac{1}{1-\sqrt{2}}-\frac{1}{\sqrt{2}-\sqrt{3}}+\frac{1}{\sqrt{3}-\sqrt{4}}-\frac{1}{\sqrt{4}-\sqrt{5}}+...+\frac{1}{\sqrt{99}-\sqrt{100}}\)

THỰC HIỆN PHÉP TÍNH \(\frac{\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}}{\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}}-\frac{\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}}{\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}}\)

Tìm lỗi sai và sửa lại

124. My friend was (A) crazy (B) although he was (C) informed of the news of his mother’s (D) death.

125. Thunder (A) is rarely heard beyond 15 miles (B) because of temperature (C) and wind vary at different (D) heights in the region around a thunderstorm.

Rewrite the sentences using the given words.

12-What would you do if you found some buried treasure? If you were……………..

13- If Paul hadn’t been interested, the project would have been abandoned. But for….

14- If by any chance you find my wallet, could you let me know? If you happen……..

15- I might be late. If so, start without me. If I……………………………………………

16- The fire was brought under control thanks to the night watch-man. If it hadn’t…...

17- Dick is in prison because a detective recognized him.

If a…………………………...