Giải:

\(\sqrt{\dfrac{0,09}{25}}=\dfrac{-4,7}{5}+x\)

\(\Leftrightarrow\dfrac{0,3}{5}=\dfrac{-4,7}{5}+x\)

\(\Leftrightarrow x=\dfrac{0,3}{5}-\dfrac{-4,7}{5}\)

\(\Leftrightarrow x=\dfrac{0,3}{5}+\dfrac{4,7}{5}\)

\(\Leftrightarrow x=\dfrac{0,3+4,7}{5}\)

\(\Leftrightarrow x=\dfrac{5}{5}=1\)

Vậy \(x=1\).

Chúc bạn học tốt!

\(\sqrt{\dfrac{1}{9}}\cdot\sqrt{0.81}+\sqrt{0.09}\)

=\(\dfrac{1}{3}\cdot\dfrac{3}{10}+\dfrac{3}{10}\)

=\(\dfrac{1}{10}+\dfrac{3}{10}\)

=\(\dfrac{2}{5}\)

\(\frac{1}{4}:\left(\frac{5}{3}\right)^{x-1}=0,09\)

\(\frac{1}{4}:\left(\frac{5}{3}\right)^{x-1}=\frac{9}{100}\)

\(\left(\frac{5}{3}\right)^{x-1}=\frac{1}{4}:\frac{9}{100}\)

\(\left(\frac{5}{3}\right)^{x-1}=\frac{1}{4}\cdot\frac{100}{9}\)

\(\left(\frac{5}{3}\right)^{x-1}=\frac{100}{36}\)

\(\left(\frac{5}{3}\right)^{x-1}=\frac{25}{9}\)

\(\left(\frac{5}{3}\right)^{x-1}=\left(\frac{5}{3}\right)^2\)

\(\Rightarrow x-1=2\Rightarrow x=3\)

Vậy x cần tìm bằng 3

=> (5/3)^x-1=25/9

=> (5/3)^x-1=(5/30)²

=> x-1=2

=> x=3

\(A=\left(0,3.5-0,5:\frac{1}{3}\right)\left(\frac{1}{2006^2}+\frac{1}{2008^2}\right)\)

\(A=\left(0,3.5-0,5.3\right)\left(\frac{1}{2006^2}+\frac{1}{2008^2}\right)\)

\(A=\left(1,5-1,5\right)\left(\frac{1}{2006^2}+\frac{1}{2008^2}\right)\)

\(A=0.\left(\frac{1}{2006^2}+\frac{1}{2008^2}\right)\)

\(A=0\)

VẬY    \(A=0\)

(0,3.5-0,5:1/3).(1/2006^2+1/2008^2)

(1,5-1,5).(1/200^2+1/2008^2)

0.(1/2006^2+1/2008^2)

0

a) x = \(\dfrac{-64}{3}\)

b) x = -3,5

c) x = 80

d) x = -1.162

e) x = 0,9436

g) x \(\in\varnothing\)

a) 16/3 : x = -1/4

=> x = 16/3 : (-1/4)

=> x = 16/3 . (-4)

=> x = -64/3

Vậy x= -64/3

b)2x - 1³ = -8

=> 2x = (-8) + 1

=> 2x = -7

=> x = -7/2

d) 0,944 - 2x = 3,268

=> 2x = 0,944 - 3,268

=> 2x = -2,324

=> x = (-2,324) : 2

=> x = -1,162

g) \(\sqrt{5^2-3^2}=-\sqrt{81-x}\)

=> \(\sqrt{25-9}\)= \(-\sqrt{81-x}\)

=> \(\sqrt{16}\)=\(-\sqrt{81-x}\)

=> 4=\(-\sqrt{81-x}\)

tới đây mik bí r hk bt lm nữa

\(\sqrt{81}=9\)

\(\sqrt{0,64}=0,8\)

\(\sqrt{\frac{49}{100}}=\frac{7}{10}\)

\(\sqrt{8100}=90\)

\(\sqrt{100=}10\)

\(\sqrt{0,01}=0,1\)

\(\sqrt{\frac{4}{25}}=\frac{2}{5}\)

\(\sqrt{\frac{0,09}{121}}=\frac{0,3}{11}\)

\(\sqrt{81}=9\);\(\sqrt{0,64}=0,8\);\(\sqrt{\frac{49}{100}}=\frac{7}{10}\);\(\sqrt{8100}=90\); \(\sqrt{100}=10\); \(\sqrt{0,01}=0,1\); \(\sqrt{\frac{4}{25}}=\frac{2}{5}\); \(\sqrt{\frac{0,09}{121}}=\frac{0,3}{11}=\frac{3}{110}\)