Question

Tìm x 5x×(3-x)-x+3

Answer 1

\(5x\left(3-x\right)-x+3=0\\ < =>5x\left(3-x\right)-\left(x-3\right)=0\\ < =>5x\left(3-x\right)+\left(3-x\right)=0\\ < =>\left(3-x\right)\left(5x+1\right)=0\\ < =>\left[{}\begin{matrix}3-x=0\\5x+1=0\end{matrix}\right.\\ < =>\left[{}\begin{matrix}x=3\\5x=-1\end{matrix}\right.\\ < =>\left[{}\begin{matrix}x=3\\x=-\dfrac{1}{5}\end{matrix}\right.\)

Vậy: ...

Answer 2

5x(3-x)-x+3=0

=>5x(3-x)+(3-x)=0

=>(3-x)(5x+1)=0

=>\(\left[{}\begin{matrix}3-x=0\\5x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-\dfrac{1}{5}\end{matrix}\right.\)