Question

3( 1 + x)^3 + 1/9 = 0

Answer 1

\(\rightarrow3\left(1+x\right)^3=-\dfrac{1}{9}\\ \rightarrow\left(1+\right)^3=-\dfrac{1}{27}\\ \left(1+x\right)^3=\left(-\dfrac{1}{3}\right)^3\\ \rightarrow1+x=-\dfrac{1}{3}\\ x=-\dfrac{1}{3}-1\\ x=-\dfrac{4}{3}\)

 

 

Answer 2

`3.(1+x)^3 + 1/9=0`

`3.(1+x)^3 =0-1/9`

`3.(1+x)^3 =-1/9`

`(1+x)^3=-1/9:3`

`(1+x)^3=-1/9xx1/3`

`(1+x)^3= -1/27`

`(1+x)^3=(-1/3)^3`

`=> 1+x=-1/3`

`x=-1/3-1`

`x=-1/3-3/3`

`x=-4/3`

Vậy `x=-4/3`