Rút gọn

\(\sqrt{15-6\sqrt{7}}\)

rút gọn

\(\sqrt{4+\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{7+4\sqrt{3}}}}}\)

Rút gọn

\(\sqrt{15-6\sqrt{6}+}+\sqrt{33-12\sqrt{6}}\)

Word formation 

1. Mary felt sorry that his condition had___________since her last visit one week earlier (bad)

2. He ______ his speech in order to get away before the marchers arrived (time)

3. It is, in many ways, a__________ if not fossilised system that we must leave behind (time)

4. Where's that ________ son of yours? I hope he isn't lazing around. (nothing)

5.  The study concludes that in a _______ scenario there might be 80,000 cases of the diseases (case)

Cho 2 số x₁,x₂ sao cho S= x₁+x₂=3 và P= x₁.x₂=2. Không tìm x₁,x₂ hãy tính giá trị các biểu thức sau

a) M= \(\dfrac{x_2^2}{x_2-1}+\dfrac{x_1^2}{x_1-1}\)

b) N= \(x_1^4+x_2^4\)

c) \(x_1^2+3x_2\)

1. Cho tam giác ABC vuông tại A, đường cao AH. Biết AB=3\(\sqrt{3}\), CH=6. Tính AC

Rút gọn:

a) \(\dfrac{x\sqrt{y}+y\sqrt{x}}{\sqrt{x}+\sqrt{y}}-\sqrt{xy}\)  với x,y>0

b) \(\left(\dfrac{\sqrt{x}-1}{\sqrt{x}+1}-\dfrac{\sqrt{x}+1}{\sqrt{x}-1}\right)\left(\sqrt{x}-\dfrac{1}{\sqrt{x}}\right)\)với x>0;x≠1

Rút gọn biểu thức

\(\dfrac{x-2\sqrt{x}}{\sqrt{x}-2}+\dfrac{x+\sqrt{x}}{\sqrt{x}+1}\)

Rút gọn:

a) \(\dfrac{x-2\sqrt{x}+1}{\sqrt{x}-1}\)

b) \(\dfrac{x-4\sqrt{x}+4}{x-2\sqrt{x}}\)

c) \(\dfrac{x\sqrt{x}+8}{\sqrt{x}+2}-x-4\)

d) \(\dfrac{x-4\sqrt{x}-5}{\sqrt{x}+1}\)