So sánh các số x và y, nếu 

a)\(x=\sqrt{961}-\left(\frac{1}{\sqrt{6}}-1\right)\)và \(y=\sqrt{1089}-\left(\frac{1}{\sqrt{7}}+1\right)\)

b) \(\sqrt{0,01}+\sqrt{0,04}+\sqrt{0,09}+\sqrt{0,16}+...+\sqrt{0,81}\)và \(y=\sqrt{20+0,25}\)

c) \(x=\left(1-\frac{1}{\sqrt{4}}\right).\left(1-\frac{1}{\sqrt{16}}\right).\left(1-\frac{1}{\sqrt{36}}\right).\left(1-\frac{1}{\sqrt{64}}\right).\left(1-\frac{1}{\sqrt{100}}\right)\)và\(y=\sqrt{0,1}\)

a)

\(\frac{3}{7}+\left(-\frac{5}{2}\right)+\left(-\frac{3}{5}\right)\)

b)

\(\frac{4}{5}-\left(-\frac{2}{7}\right)-\frac{7}{10}\)

c)

\(3,5-\left(-\frac{2}{7}\right)\)

d)

\(\sqrt{\left(-7\right)^2}+\sqrt{\frac{25}{16}}-\frac{3}{2}\)

e)

\(\sqrt{0,36}.\sqrt{\frac{25}{16}}+\frac{1}{4}\)

f)

\(\frac{1}{2}.\sqrt{100}-\sqrt{\frac{1}{16}}+\left(\frac{1}{3}\right)^0\)

g)

\(\sqrt{\frac{4}{81}}:\sqrt{\frac{25}{81}}-1\frac{2}{5}\)

i)

\(\frac{21^9.2^{10}}{14^9.3^8}\)

k)

\(\frac{10^{11}.21^{12}}{15^{10}.14^{11}}\)

l)

\(0,5.\sqrt{100}-\sqrt{\frac{1}{4}}\)

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

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

Tính x.y

Mn ơi, giúp mk nha, mai mk nộp òi!

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.Chứng tỏ rằng:

A=75.(4²⁰⁰⁴+4²⁰⁰³+...+4²+4+1)+25 chia hết cho 100

2.tính nhanh:

\(A=\frac{\left(1+2+3+...+99+100\right)\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{7}-\frac{1}{9}\right)\left(63.1,2-21.3,6\right)}{1-2+3-4+...+99-100}\)

\(B=\frac{\left(\frac{1}{14}-\frac{\sqrt{2}}{7}+\frac{\sqrt[3]{2}}{35}\right).\left(-\frac{4}{15}\right)}{\left(\frac{1}{10}+\frac{\sqrt[3]{2}}{25}-\frac{\sqrt{2}}{5}\right).\frac{5}{7}}\)

3.a)tính giá trị của biểu thức A=3x²-2x+1 với |x|=\(\frac{1}{2}\)

b)Tìm x nguyên để \(\sqrt{x+1}\)chia hết cho \(\sqrt{x-3}\)

tính

\(\left\{\left[\left(2\sqrt{2}\right)^2:2,4\right].\left[5,25:\left(\sqrt{7}\right)^2\right]\right\}:\left\{\left[2\frac{1}{7}:\frac{\left(\sqrt{5}\right)^2}{7}\right]:\left[2^3:\frac{\left(2\sqrt{2}\right)^2}{\sqrt{81}}\right]\right\}\)

tìm x,y,x

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

so sánh A và B:

\(A=\sqrt{225}-\frac{1}{\sqrt{5}}-1\)           \(B=\sqrt{196}-\frac{1}{\sqrt{6}}\)

ai giải đc câu nào thì giải giúp với