Đáp án:
S={0; 1/3; -7/3; -2}
Giải thích các bước giải:
(3x-2).(x+1)².(3x+8)=-16
⇔(9x²+24x-6x-16).(x²+2x+1)=-16
⇔(9x²+18x-16).(x²+2x+1)=-16
⇔$9x^{4}$ +$18x^{3}$+$9x^{2}$ +$18x^{3}$+ $36x^{2}$ +18x-$16x^{2}$ -32x-16=-16
⇔$9x^{4}$ +$18x^{3}$ +$9x^{2}$ +$18x^{3}$ +$36x^{2}$+18x- $16x^{2}$ -32x=0
⇔$9x^{4}$ +$36x^{3}$ +$29x^{2}$ -14x=0
⇔x. ($9x^{3}$ + 36$x^{2}$ +29x-14)= 0
⇔ x(9$x^{3}$ -3$x^{2}$ +39$x^{2}$ -13x+42x-14)=0
⇔x.(3x-1).(3$x^{2}$ +13x+14)=0
⇔ x(3x-1).(3$x^{2}$ +7x+6x+14)=0
⇔x(3x-1).(3x+7).(x+2)=0
⇔\(\left[ \begin{array}{l}x=0\\3x-1=0\end{array} \right.\)
\(\left[ \begin{array}{l}3x+7=0\\x+2=0\end{array} \right.\)
⇔ \(\left[ \begin{array}{l}x=0\\x=1/3\end{array} \right.\)
\(\left[ \begin{array}{l}x=-7/3\\x=-2\end{array} \right.\)
S={0; 1/3; -7/3; -2}
