Question

x : 5=20 : x

Answer 1

=>x²=100

=>x=10 hoặc x=-10

Answer 2

giúp mình vs mik cần gấp

 

 

Answer 3

Ta có x/5=20/x<=> x² =5x20

x² =100 <=> x²=10²

=>x=10

Answer 4

\(x:5=20:x\left(đk:x\ne0\right)\)

\(\Leftrightarrow\dfrac{x}{5}=\dfrac{20}{x}\)

\(\Leftrightarrow x^2=100\)

\(\Leftrightarrow\left|x\right|=10\)

\(\left[{}\begin{matrix}x=10\\x=-10\end{matrix}\right.\)

Answer 5

\(\dfrac{x}{5}=\dfrac{20}{x}\)

➩x.x=5.20

➩x.x=100

➩x.x=±10.±10

➩x=±10