\(\frac{x}{0,16}=\frac{9}{x}\Rightarrow x^2=\frac{36}{25}\Rightarrow x=\frac{6}{5}\)hoặc \(x=-\frac{6}{5}\)

\(\frac{x}{0,16}=\frac{9}{x}\Rightarrow x^2=\frac{36}{25}\Rightarrow x=\frac{6}{5}\)hoặc \(x=-\frac{6}{5}\)

x:0.16=9:x

\(\frac{4}{x}=\frac{x}{0,16}\)

\(x\cdot x=4\cdot0,16\)

\(x^2=\frac{16}{25}\)

\(x^2=\left(\frac{\pm4}{5}\right)^2\)

\(\Rightarrow x\in\left\{\frac{4}{5};\frac{-4}{5}\right\}\)

\(\frac{4}{x}=\frac{x}{0.16}\)

\(\Rightarrow x\cdot x=4\cdot0.16\)

\(x^2=4\cdot0.16\)

\(x^2=\frac{16}{25}\)

\(\Rightarrow\orbr{\begin{cases}x=\left(\frac{4}{5}\right)^2\\\left(\frac{-4}{5}\right)^2\end{cases}}\)

4÷x=x÷0,16

x×x=4×0,16

x^2=0,64

x=0,8

x=-0,8

1/500

0.16:x=20.4

x = 0.16 : 20.4

x = 16/100 *  2040/100

x =  2/25 * 255/25

x = 102/137

0.16:x=20.4

x=0.16/20.4

x=127.5

\(0,16\text{ : }x=2-0,4\)

\(0,16\text{ : }x=1,6\)

             \(x=0,16\text{ : }1,6\)

             \(x=0,1\)

\(\text{Chúc bạn học tốt !}\)

0,16 : x = 2 - 0,4

0,16 : x = 1,6

x= 0,16 : 1,6 

x= 0,1

0,16:x=2-0,4

0,16:x=1,6

      x  =0,16:1,6

      x  =0,1

0,16 : ( x : 3,5) = 2,8

x : 3,5 = 0,16 : 2,8

x  =  0,16 : 2,8 x 3,5

x  =  0,2

Thử lại: 0,16 : (0,2 : 3,5) = 2,8 (đúng)