Question

giải phương trình : 2x⁵ - 5x² + 3 = 0

Answer 1

Ta có: \(2x^5-5x^2+3=0\)

\(\Leftrightarrow2x^5-2x^2-3x^2+3=0\)

\(\Leftrightarrow2x^2\left(x^3-1\right)-3\left(x^2-1\right)=0\)

\(\Leftrightarrow2x^2\left(x-1\right)\left(x^2+x+1\right)-3\left(x-1\right)\left(x+1\right)=0\)

\(\Leftrightarrow\left(x-1\right)\left[2x^2\left(x^2+x+1\right)-3\left(x+1\right)\right]=0\)

\(\Leftrightarrow\left(x-1\right)\left(2x^4+2x^3+2x^2-3x-3\right)=0\)

Bạn tự c/m \(2x^4+2x^3+2x^2-3x-3\ne0\) nhé

Do đó: x-1=0

hay x=1

Vậy: x=1