2 câu trả lời
`(x-3)(2x^2+3)=0`
`→`\(\left[ \begin{array}{l}x-3=0\\2x^2+3=0\end{array} \right.\)
`→`\(\left[ \begin{array}{l}x=3\\2x^2=-3\end{array} \right.\)
`→`\(\left[ \begin{array}{l}x=3\\x^2=-1,5\end{array} \right.\)
`→`\(\left[ \begin{array}{l}x=3\\x^2∈∅\end{array} \right.\)
Vậy `x=3`
Lời giải:
`(x - 3)(2x^2 + 3) = 0`
$\left[\begin{matrix} x - 3 = 0\\ 2x^2 + 3 = 0\end{matrix}\right.$
$\left[\begin{matrix} x = 0 + 3\\ 2x^2 = -3\end{matrix}\right.$
$\left[\begin{matrix} x = 3\\ x^2 = -3 : 2\end{matrix}\right.$
$\left[\begin{matrix} x = 3\\ x^2 = -1,5\end{matrix}\right.$
$\left[\begin{matrix} x = 3\\ x^2 = -1,5\end{matrix}\right.$
$\left[\begin{matrix} x = 3\\ x \in \varnothing\end{matrix}\right.$
Vậy `x = 3`