Mình ko biết cách tách đặc biệt bằng máy tính.
a, 3x²-11x+6 =0
(3x²-9x)-(2x-6)=0
3x(x-3)-2(x-3) =0
(3x-2)(x-3) =0
⇒ \(\left[ \begin{array}{l}3x-2=0\\x-3=0\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}3x=2\\x=3\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=\frac{2}{3}\\x=3\end{array} \right.\)
b. -2x²+5x+3 = 0
-(2x²-5x-3) = 0
⇒ (2x²-6x)+(x-3)= 0
2x(x-3)+(x-3) = 0
(2x+1)(x-3) = 0
⇒ \(\left[ \begin{array}{l}2x+1=0\\x-3=0\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}2x=-1\\x=3\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=\frac{-1}{2}\\x=3\end{array} \right.\)
c. x²+2x-3 =0
(x²+2x+1)-4 =0
(x+1)²-2² =0
(x+1+2)(x+1-2)=0
(x+3)(x-1) =0
⇒ \(\left[ \begin{array}{l}x+3=0\\x-1=0\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=-3\\x=1\end{array} \right.\)
d. x²-4x-5 =0
(x²-2.x.2+4)-9 =0
(x-2)²-3² =0
(x-2+3)(x-2-3) =0
(x+1)(x-5) =0
⇒ \(\left[ \begin{array}{l}x+1=0\\x-5=0\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=-1\\x=5\end{array} \right.\)
Xin hay nhất ạ >.<
