Question

Giải các phương trình sau:

a) x² - 3x + 2 = 0

b) 2x² + 5x + 3 = 0

Answer 1

a) \(\Leftrightarrow x^2-x-2x+2=0\)

\(\Leftrightarrow x\left(x-1\right)-2\left(x-1\right)=0\)

\(\Leftrightarrow\left(x-1\right)\left(x-2\right)=0\)

\(\Leftrightarrow\left\{{}\begin{matrix}x-1=0\\x-2=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=1\\x=2\end{matrix}\right.\)

Vậy S={1,2}
b) \(\Leftrightarrow\)2x² +2x+3x +3 = 0
\(\Leftrightarrow\) 2x(x+1)+3(x+1) = 0

\(\Leftrightarrow\)(x+1)(2x+3) = 0

\(\Leftrightarrow\)\(\left\{{}\begin{matrix}x+1=0\\2x+3=0\end{matrix}\right.\) \(\Leftrightarrow\)\(\left\{{}\begin{matrix}x=-1\\x=\frac{-3}{2}\end{matrix}\right.\)

Vậy S={-1; \(\frac{-3}{2}\)}

Answer 2

Answer 3

x^-3x+2=0

<=>x^-2x-x+2=0

rùi làm như bình thường