Question

tìm x trong tỉ lệ thức sau

x:0,2=0,8:x

Answer 1

x:0,2=0,8:x

\(\dfrac{x}{0,2}=\dfrac{0,8}{x}\\ \Leftrightarrow x.x=0,8.0,2\\ \Rightarrow x^2=0,16\\ \Rightarrow x^2=\left(\pm0,4\right)^2\\ \Rightarrow x=\pm0,4\)

Vậy...

Answer 2

\(\dfrac{x}{0,2}=\dfrac{0,8}{x}\)

\(\Leftrightarrow x.x=0,2.0,8\)

\(\Leftrightarrow x^2=0,16\)

\(\Leftrightarrow x^2=\left(0,4\right)^2\)

\(\Leftrightarrow x=0,4\)

Answer 3

\(\dfrac{x}{0,2}=\dfrac{0,8}{x}\)

\(\Leftrightarrow x.x=0,2.0.8\)

\(\Leftrightarrow x^1.x^1=0,16\)

\(\Leftrightarrow x^2=\left(0,4\right)^2\)

\(\Rightarrow x=0,4\)