bài 1 So sánh

a, \(\sqrt{50}+\sqrt{39}+3\) và 16

b, \(\sqrt{3}+\sqrt{8}+2\) và 7

c, \(2\sqrt{26}+3\sqrt{64}-5\) và 28

bài 2 Tính nhanh

a, \(\sqrt{4}+\sqrt{25}+\sqrt{64}+...+\sqrt{2500}\)

b, \(\sqrt{1}+\sqrt{25}+\sqrt{81}+...+\sqrt{9409}\)

c, \(\sqrt{\frac{1}{4}}+\sqrt{\frac{1}{36}}+\sqrt{\frac{1}{144}}+...+\sqrt{\frac{1}{9900^2}}\)

Rút gọn

1,\(2\sqrt{\frac{16}{3}}-3\sqrt{\frac{1}{27}}-6\sqrt{\frac{4}{75}}\)

2,\(\left(2\sqrt{\frac{16}{3}}-3\sqrt{\frac{1}{27}}-6\sqrt{\frac{4}{75}}\right)\sqrt{3}\)

3,\(\left(6\sqrt{\frac{8}{9}}-5\sqrt{\frac{32}{25}}+14\sqrt{\frac{18}{49}}\right)\sqrt{\frac{1}{2}}\)

4,\(\frac{1}{2}\sqrt{48}-2\sqrt{75}-\frac{\sqrt{33}}{\sqrt{11}}+5\sqrt{1\frac{1}{3}}\)

5,\(\left(\sqrt{\frac{1}{7}}-\sqrt{\frac{16}{7}}+\sqrt{7}\right):\sqrt{7}\)

Rút Gọn

a,\(\sqrt{75}-\sqrt{5\frac{1}{3}}+\frac{9}{2}\sqrt{2\frac{2}{3}}+2\sqrt{27}\)

b,\(\sqrt{48}+\sqrt{5\frac{1}{3}}+2\sqrt{75}-5\sqrt{1\frac{1}{3}}\)

c,\(\left(\sqrt{12}+2\sqrt{27}\right)\frac{\sqrt{3}}{2}-\sqrt{150}\)

d,\(\left(\sqrt{18}+\sqrt{0,5}-3\sqrt{\frac{1}{3}}\right)-\left(\sqrt{\frac{1}{8}-\sqrt{75}}\right)\)

e,\(6\sqrt{\frac{8}{9}}-5\sqrt{\frac{32}{25}}+14\sqrt{\frac{18}{49}}\)

f,\(2\sqrt{\frac{16}{3}}-3\sqrt{\frac{1}{27}}-6\sqrt{\frac{4}{75}}\)

g,\(\left(2\sqrt{\frac{16}{3}}-3\sqrt{\frac{1}{27}}-6\sqrt{\frac{4}{75}}\right)\sqrt{3}\)

h,\(\left(6\sqrt{\frac{8}{9}}-5\sqrt{\frac{32}{25}}+14\sqrt{\frac{18}{49}}\right)\sqrt{\frac{1}{2}}\)

i,\(\frac{1}{2}\sqrt{48}-2\sqrt{75}-\frac{\sqrt{33}}{\sqrt{11}}+5\sqrt{1\frac{1}{3}}\)

j,\(\left(\sqrt{\frac{1}{7}}-\sqrt{\frac{16}{7}}+7\right):\sqrt{7}\)

Tìm các giá trị của x để căn thức sau có nghĩa:

a) \(\sqrt{4-5x}\)

b) \(\sqrt{\frac{x^2+1}{x-3}}\)

c) \(\sqrt{\frac{x-1}{x^2+2}}\)

d) \(\sqrt{\frac{2x-3}{x-1}}\)

e) \(\frac{\sqrt{2x-3}}{\sqrt{x-1}}\)

2/ Thực hiện phép tính:

a) \(\sqrt{\frac{16}{64}\cdot\frac{144}{9}\cdot\frac{25}{196}}\)

b) \(\left(\sqrt{8}+5\sqrt{2}-\sqrt{20}\right)\sqrt{5}-7\sqrt{10}\)

RÚT GỌN BIỂU THỨC 

A=\(\frac{a-b}{\sqrt{a}-\sqrt{b}}-\frac{\sqrt{a^3}-\sqrt{b^3}}{a-b}\)(với a>_ 0, b>_ 0, a#b)

B=\(\left(\frac{\sqrt{x^3}+\sqrt{y^3}}{\sqrt{x}+\sqrt{y}}-\sqrt{xy}\right).\left(\frac{\sqrt{x}+\sqrt{y}}{x-y}\right)\)(với  x>_ 0, y>_ 0, x#y)

C=\(x-4-\sqrt{16-8x^2+x^4}\)(với x>4)

D=\(\frac{a+b-2\sqrt{ab}}{\sqrt{a}-\sqrt{b}}:\frac{1}{\sqrt{a}+\sqrt{b}}\)(với a>0, b>0, a#b)

E=\(\left(2+\frac{a-\sqrt{a}}{\sqrt{a}-1}\right).\left(2-\frac{a+\sqrt{a}}{\sqrt{a}+1}\right)\)(với a>0, a#1)

F=\(\frac{a-3\sqrt{a}}{\sqrt{a}-3}-\frac{a+4\sqrt{a}+3}{\sqrt{a}+3}\)( với a>_ 9)

G=\(\frac{9-x}{\sqrt{x}+3}-\frac{9-6\sqrt{x}+x}{\sqrt{x}-3}-6\)( với x>_ 9 )