Question

2x-x^2=-3. Tìm x

Answer 1

\(2x-x^2=-3\)

\(\Leftrightarrow x^2-2x-3=0\)

\(\Leftrightarrow\left(x-3\right)\left(x+1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-1\end{matrix}\right.\)

Answer 2

-x²+2x+3=0

<=>-x^2-x+3x+3=0

<=>-x(x+1)+3.(x+1)=0

<=> (x+1).(3-x)=0

vậy x = -1 hoặc x=3