Bài làm:

Ta có: \(\left[\left(2x-0,3\right)-2\right]=8\)

\(\Leftrightarrow2x-0,3=10\)

\(\Leftrightarrow2x=10,3\)

\(\Leftrightarrow x=5,15\)

\(\left\{\left[2x-0,3\right]-2\right\}=8\)

= \(\left[2x-0,3\right]=10\)

= 2x = 10,3

x = 5,15

\(\frac{33}{8}:\frac{1}{5}=x:\frac{3}{10}\)

\(\Rightarrow\frac{165}{8}=x:\frac{3}{10}\)

\(\Rightarrow x=\frac{99}{16}\)

study well 

33/8:0,2=x:0,3

33/8:1/5=x:3/10

33/8.5=x:3/10

165/8=x:3/10

165/8.3/10=x

=>x=99/80

Vậy x=99/80

   Hok tốt

\(\left(152\frac{2}{4}-148\frac{3}{8}\right):0,2=x:0,3\)
      \(\left(\frac{305}{2}-\frac{1187}{8}\right):\frac{1}{5}=x:0,3\) 
                                     \(\frac{33}{8}.5=x:0,3\)
                                       \(\frac{165}{8}=x:0,3\)
                                       \(x:0,3=\frac{165}{8}\)
                                               \(x=\frac{99}{16}\)
Vậy \(x=\frac{99}{16}\)

0,3x0,3x0,3= 0,3^3 = 0,027

☢

\(\left(152\frac{2}{4}-148\frac{3}{8}\right):0,2=x:0,3\)

\(\frac{33}{8}\) : 0,2= x:0,3

x:0,3 = 165/8

x= 165/8 . 0,3

x=99/16

a) \(\frac{-3}{7}+x=\frac{1}{3}\)

\(\Leftrightarrow x=\frac{1}{3}+\frac{3}{7}\)

\(\Leftrightarrow x=\frac{16}{21}\)

b) \(\frac{-5}{8}+x=\frac{-2^2}{3}\)

\(\Leftrightarrow x=\frac{-4}{3}+\frac{5}{8}\)

\(\Leftrightarrow x=-\frac{17}{24}\)

c) \(4\frac{1}{3}:\frac{x}{4}=6:0,3\)

\(\Leftrightarrow\frac{8}{3}:\frac{x}{4}=20\)

\(\Leftrightarrow\frac{32}{3x}=20\)

\(\Leftrightarrow3x=\frac{8}{5}\)

\(\Leftrightarrow x=\frac{8}{15}\)

a)4,5:0,3=2,25:(0,1.x)

   2,25:(0,1.x)=15

   0,1.x=0,15

   x=0,15:0,1

   x=1,5

Vậy x=1,5

b)8:\(\left(\frac{1}{4}.x\right)\)=2:0,02

   8:\(\left(\frac{1}{4}.x\right)\)=100

       \(\left(\frac{1}{4}.x\right)\)=\(\frac{8}{100}\)

        x=\(\frac{8}{100}\):\(\frac{1}{4}\)

         x=\(\frac{8}{25}\)

Vậy x=\(\frac{8}{25}\)

c)\(3:2\frac{1}{4}=\frac{3}{4}:\left(6.x\right)\)

   \(\frac{3}{4}:\left(6.x\right)=\frac{4}{3}\)

    6.x=\(\frac{3}{4}:\frac{4}{3}\)

    6.x=\(\frac{9}{16}\)

    x=\(\frac{9}{16}\):6

    x=\(\frac{3}{32}\)

Vậy x=\(\frac{3}{32}\)

a.

\(4,5\div0,3=2,25\div\left(0,1\times x\right)\)

\(2,25\div\left(0,1\times x\right)=15\)

\(0,1\times x=\frac{2,25}{15}\)

\(0,1\times x=0,15\)

\(x=\frac{0,15}{0,1}\)

\(x=1,5\)

b.

\(8\div\left(\frac{1}{4}\times x\right)=2\div0,02\)

\(8\div\left(\frac{1}{4}\times x\right)=100\)

\(\frac{1}{4}\times x=\frac{8}{100}\)

\(\frac{1}{4}\times x=\frac{2}{25}\)

\(x=\frac{2}{25}\div\frac{1}{4}\)

\(x=\frac{2}{25}\times4\)

\(x=\frac{8}{25}\)

c.

\(3\div2^1_4=\frac{3}{4}\div\left(6\times x\right)\)

\(\frac{3}{4}\div\left(6\times x\right)=3\div2,25\)

\(\frac{3}{4}\div\left(6\times x\right)=\frac{4}{3}\)

\(6\times x=\frac{3}{4}\div\frac{4}{3}\)

\(6\times x=\frac{3}{4}\times\frac{3}{4}\)

\(6\times x=\frac{9}{16}\)

\(x=\frac{9}{16}\div6\)

\(x=\frac{9}{16}\times\frac{1}{6}\)

\(x=\frac{3}{32}\)

                                              Bài giải

Ta có : \(9^{99}=\left(9^{11}\right)^9\)

Vì \(\left(9^{11}\right)^9>99^9\text{ }\left[\left(81\cdot9^9\right)^9>99^9\right]\text{ }\Rightarrow\text{ }9^{99}>99^9\)

                                              Bài giải

Ta có : \(9^{99}=\left(9^{11}\right)^9\)

Vì \(\left(9^{11}\right)^9>99^9\text{ }\left[\left(81\cdot9^9\right)^9>99^9\right]\text{ }\Rightarrow\text{ }9^{99}>99^9\)