Đáp án:
a) x=1
Giải thích các bước giải:
\(\begin{array}{l}
a)2x + x\left( {{x^2} - 1} \right) = {x^3} + 1\\
\to {x^3} - x + 2x = {x^3} + 1\\
\to x = 1\\
b)\dfrac{{3\left( {x - 1} \right) + 2\left( {x - 1} \right) - x + 1 - 2.6}}{6} = 0\\
\to 5x - 5 - x - 11 = 0\\
\to 4x = 16\\
\to x = 4\\
c)\dfrac{{x + 2}}{5} - \dfrac{1}{2}x = \dfrac{{1 - 2x}}{4} + \dfrac{1}{4}\\
\to \dfrac{{4x + 8 - 10x - 5 + 10x - 5}}{{20}} = 0\\
\to 4x = 2\\
\to x = \dfrac{1}{2}\\
d)\dfrac{{3{x^2} + 5x - 2}}{3} - \dfrac{{2{x^2} - 10}}{2} = 0\\
\to \dfrac{{6{x^2} + 10x - 4 - 6{x^2} + 30}}{6} = 0\\
\to 10x = - 26\\
\to x = - \dfrac{{13}}{5}
\end{array}\)
