Question

Answer 1

\(\left(2x-1\right)^3+8=0\\ < =>\left(2x-1\right)^3=-8=\left(-2\right)^3\\ =>2x-1=-2\\ < =>x=-\dfrac{1}{2}\)

\(x^3-3x^2+3x-2=0\\ < =>x^3-3.x^2.1+3.x.1^2-1^3-1=0\\ < =>\left(x-1\right)^3=1=1^3\\ =>x-1=1\\ < =>x=2\)

Answer 2

\(1,\left(2x-1\right)^3=-8\\ \left(2x-1\right)^3=\left(-2\right)^3\\ 2x-1=-2\\ 2x=-1\\ x=\dfrac{-1}{2}\\ 2,\left(x^3-3x^2+3x-1\right)-1=0\\ \left(x-1\right)^3-1=0\\ \left(x-1\right)^3=1^3\\ x-1=1\\ x=2\)

Answer 3

1,=>(2x-1)³=8=(-2)³

=>2x-1=-2

=>2x=-1

=>x=-½

Còn phần 2 thì bạn học những hằng đẳng thức đáng nhớ chưa