1. a) \(\sqrt{9}+\sqrt{4}\)      b) \(\sqrt{0,25}-\sqrt{0,01}\)   c) \(\sqrt{\frac{16}{25}}-\sqrt{\frac{1}{81}}\)    d) \(2-\sqrt{0,36}\)

2.  a) \(\sqrt{64}-\sqrt{16}+\sqrt{\left(-3^2\right)}\)       b) \(\sqrt{121}+\sqrt{\left(-5\right)^2}-\sqrt{9}\)

c) \(\sqrt{\frac{9}{4}}-\sqrt{\frac{16}{36}}-\sqrt{49}\)      d) \(\sqrt{\left(-4\right)^2}+\sqrt{\left(-5\right)^2}-\sqrt{\left(-6\right)^2}\)

\(Cho\)\(x=\left(1+\frac{1}{\sqrt{1}}\right)+\left(1+\frac{1}{\sqrt{9}}\right)+\left(\frac{1}{\sqrt{25}}\right)+\left(1+\frac{1}{\sqrt{49}}\right)+\left(1+\frac{1}{\sqrt{81}}\right)\)

            \(y=\left(1+\frac{1}{\sqrt{4}}\right)+\left(1+\frac{1}{\sqrt{16}}\right)+\left(1+\frac{1}{\sqrt{36}}\right)+\left(1+\frac{1}{\sqrt{64}}\right)+\left(1+\frac{1}{\sqrt{100}}\right)\)

Tính x.y

Mn ơi, giúp mk nha, mai mk nộp òi!

a,\(\left(\frac{2^2}{5}\right)\)+\(5\frac{1}{2}\).(4,5-2,5)+\(\frac{2^3}{-4}\)

b,\(\left(-2^3\right)\)+\(\frac{1}{2}\):\(\frac{1}{8}\)-\(\sqrt{25}\)+|-64|

c,\(\frac{\sqrt{3^2+\sqrt{39}^2}}{\sqrt{91^2}-\sqrt{\left(-7^2\right)}}\)
d,\(\left(-2^2\right)+\sqrt{36}-\sqrt{9}+\sqrt{25}20.20\))
e,\(\sqrt{25}-3\sqrt{\frac{4}{9}}\)

h,\(\left(-3^2\right)\).\(\frac{1}{3}\)-\(\sqrt{49}\)+\(\left(5^3\right)\):\(\sqrt{25}\)

Bài 1: Thực hiện phép tính:

a,\(\left(\frac{-3}{4}+\frac{2}{7}\right):\frac{2}{7}+\left(\frac{-1}{4}+\frac{5}{7}\right):\frac{2}{3}\)

b,\(\left(-\frac{1}{3}\right)^2\cdot\frac{4}{11}+\frac{7}{11}\cdot\left(-\frac{1}{3}\right)^2\)

c, \(\left(-\frac{1}{7}\right)^0-2\frac{4}{9}\cdot\left(\frac{2}{3}\right)^2\)

d,\(\frac{2^7\cdot9^2}{3^3\cdot2^5}\)

e,\(\left(\frac{1}{3}-\frac{5}{6}\right)^2+\frac{5}{6}:2\)

f,\(\left(9\frac{2}{4}:5,2+3.4\cdot2\frac{7}{34}\right):\left(-1\frac{9}{16}\right)\)

g,\(\sqrt{25}-3\sqrt{\frac{4}{9}}\)

h,\(\left(-2\right)^2+\sqrt{36}-\sqrt{9}+\sqrt{25}\)

i,\(\left(-\frac{1}{2}\right)^4+\left|-\frac{2}{3}\right|-2007^0\)

k,\(\left(-2\right)^3+\frac{1}{2}:\frac{1}{8}-\sqrt{25}+\left|-64\right|\)

m,\(\left(-3\right)^2\cdot\frac{1}{3}-\sqrt{49}+\left(-5\right)^3:\sqrt{25}\)

n,\(\frac{\sqrt{3^2+\sqrt{39^2}}}{\sqrt{91^2}-\sqrt{\left(-7\right)^2}}\)

1) Rút gọn biểu thức theo là cách hợp lý:

A = \(\frac{1-\frac{1}{\sqrt{49}}+\frac{1}{49}-\frac{1}{\left(7\sqrt{7}\right)^2}}{\frac{\sqrt{64}}{2}-\frac{4}{7}+\left(\frac{2}{7}\right)^2-\frac{4}{343}}\)

2) Tính hợp lý:

M = \(1-\frac{5}{\sqrt{196}}-\frac{5}{\left(2\sqrt{21}\right)^2}-\frac{\sqrt{25}}{204}-\frac{\left(\sqrt{5}\right)^2}{374}\)

3) Có hay không giá trị của x thỏa mãn điều kiện sau:

\(2002.\sqrt{\left(1+x\right)^2}+2003.\sqrt{\left(1-x\right)^2}=0\)

4) Tìm các số x, y, z thỏa mãn đẳng thức:

\(\sqrt{\left(x-\sqrt{2}\right)^2}+\sqrt{\left(y+\sqrt{2}\right)^2}+\left|x+y+z\right|=0\)