Question

Giải phương trình: \(x^3+1+\left(x^2-x+1\right)=0\)

Answer 1

\(\Rightarrow\left(x+1\right)\left(x^2-x+1\right)+\left(x^2-x+1\right)=0\)

\(\Rightarrow\left(x^2-x+1\right)\left(x+1+1\right)=0\)

\(\Rightarrow\left(x^2-x+1\right)\left(x+2\right)=0\)

=> x² - x + 1 = 0 mà x² - x + 1 > 0 => vô nghiệm

hoặc x + 2 = 0 => x = -2

Vậy x = -2

Answer 2

tui bổ sung cho Angela nhá:

\(x^2-x+1=x^2-2x.\frac{1}{2}+\frac{1}{4}+\frac{3}{4}=\left(x-\frac{1}{2}\right)^2+\frac{3}{4}>0\)