\(2x^2+3x-2=0\)
\(\Rightarrow2x^2-x+4x-2=0\)
\(\Rightarrow x.\left(2x-1\right)+2.\left(2x-1\right)=0\)
\(\Rightarrow\left(2x-1\right).\left(x+2\right)=0\)
\(\Rightarrow\left[\begin{array}{nghiempt}2x-1=0\\x+2=0\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}2x=1\\x=-2\end{array}\right.\)
\(\Rightarrow\left[\begin{array}{nghiempt}x=\frac{1}{2}\\x=-2\end{array}\right.\)
\(2x^2+3x-2=0\)
\(\Leftrightarrow2x^2+4x-x-2=0\)
\(\Leftrightarrow2x\left(x+2\right)-\left(x+2\right)=0\)
\(\Leftrightarrow\left(2x-1\right)\left(x+2\right)=0\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}2x-1=0\\x+2=0\end{array}\right.\)\(\Leftrightarrow\left[\begin{array}{nghiempt}x=\frac{1}{2}\\x=-2\end{array}\right.\)
\(2x^2+3x-2=0\)
\(\Delta=3^2-4.2.\left(-2\right)=25\)
\(X_1=\frac{-3+\sqrt{25}}{4}=\frac{1}{2}\)
\(X_2=\frac{-3-\sqrt{25}}{4}=-2\)
