Question

Answer 1

`a)\root[3]{x}=-1,5`

`<=>x=-3,375`

Vậy `S={-3,375}`

______________________

`b)\root[3]{x-5}=0,9`

`<=>x-5=0,729`

`<=>x=5,729`

Vậy `S={5,729}`

Answer 2

`a.`\(\sqrt[3]{x}=-1,5\)

\(\Leftrightarrow\left(\sqrt[3]{x}\right)^3=\left(-1,5\right)^3\)

\(\Leftrightarrow x=-3,375\)

Vậy \(S=\left\{-3,375\right\}\)

`b.`\(\sqrt[3]{x-5}=0,9\)

\(\Leftrightarrow\left(\sqrt[3]{x-5}\right)^3=\left(0,9\right)^3\)

`<=>x-5=0,729`

`<=>x=5,729`

Vậy \(S=\left\{5,729\right\}\)

 

Answer 3

`a, x = -1,5^3 = -3,375`

`b,x - 5 = 0,9^3`

`x = 0,729 + 5`

`x = 5,729`