Question

GIẢI PHƯƠNG TRÌNH

x^3_x^2_x = \(\dfrac{1}{3}\)

^{giải nhanh giùm mình với}

Answer 1

\(PT\Leftrightarrow3x^3-3x^2-3x=1\)

\(\Leftrightarrow3x^3=3x^2+3x+1\)

\(\Leftrightarrow4x^3=\left(x+1\right)^3\Leftrightarrow x+1=\sqrt[3]{4}x\)

\(\Leftrightarrow x=\dfrac{1}{\sqrt[3]{4}-1}\)

Answer 2

x³ - x² - x = 1/3
<=> x³ = x² + x + 1/3
<=> 3x³ = 3(x² + x + 1/3)
<=> 3x³ = 3x² + 3x + 1
<=> 3x³ + x³ = x³ + 3x² + 3x + 1
<=> 4x³ = (x + 1)³
<=> ³√(4x³) = ³√(x + 1)³
<=> ³√4.x = x + 1
<=> ³√4.x - x = 1
<=> x(³√4 - 1) = 1
<=> x = 1/(³√4 - 1)