Question

tìm x (2/5-x)^3 .50% =1/2

Answer 1

`(2/5-x)^3*50%=1/2`

`=>(2/5-x)^3*1/2=1/2`

`=>(2/5-x)^3=1/2:1/2`

`=>(2/5-x)^3=1`

`=>2/5-x=1`

`=>x=2/5-1`

`=>x=2/5-5/5`

`=>x=-3/5`

Answer 2

 

Answer 3

\(\left(\dfrac{2}{5}-x\right)^3\times50\%=\dfrac{1}{2}\\ \Rightarrow\left(\dfrac{2}{5}-x\right)^3\times\dfrac{1}{2}=\dfrac{1}{2}\\ \Rightarrow\left(\dfrac{2}{5}-x\right)^3=\dfrac{1}{2}:\dfrac{1}{2}\\ \Rightarrow\left(\dfrac{2}{5}-x\right)^3=\dfrac{1}{2}\times2\\ \Rightarrow\left(\dfrac{2}{5}-x\right)^3=1\\ \Rightarrow\dfrac{2}{5}-x=1\\ \Rightarrow x=\dfrac{2}{5}-1\\ \Rightarrow x=\dfrac{2}{5}-\dfrac{5}{5}\\ \Rightarrow x=\dfrac{-3}{5}\)