Đáp án:
CHÚC BẠN HỌC TỐT!!!
Giải thích các bước giải:
$a, 24x^2-x-3=0$
$⇔24x^2+8x-9x-3=0$
$⇔8x(3x+1)-3(3x+1)=0$
$⇔(3x+1)(8x-3)=0$
\(⇔\left[ \begin{array}{l}3x+1=0\\8x-3=0\end{array} \right.\) \(⇔\left[ \begin{array}{l}x=-\dfrac{1}{3}\\x=\dfrac{3}{8}\end{array} \right.\)
$b, 3x^2+8x+4=0$
$⇔3x^2+6x+2x+4=0$
$⇔3x(x+2)+2(x+2)=0$
$⇔(3x+2)(x+2)=0$
\(⇔\left[ \begin{array}{l}3x+2=0\\x+2\end{array} \right.\) \(⇔\left[ \begin{array}{l}x=-\dfrac{2}{3}\\x=-2\end{array} \right.\)
$c, 6x^2+x-12=0$
$⇔6x^2-8x+9x-12=0$
$⇔2x(3x-4)+3(3x-4)=0$
$⇔(3x-4)(2x+3)=0$
\(⇔\left[ \begin{array}{l}3x-4=0\\2x+3=0\end{array} \right.\) \(⇔\left[ \begin{array}{l}x=\dfrac{4}{3}\\x=-\dfrac{3}{2}\end{array} \right.\)
