Question

tìm x biết 

a) x(x -2 ) + x - 2 = 0

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

Answer 1

a)  \(x\left(x-2\right)+x-2=0\)

<=>   \(\left(x-2\right)\left(x+1\right)=0\)

<=>  \(\orbr{\begin{cases}x-2=0\\x+1=0\end{cases}}\)

<=>  \(\orbr{\begin{cases}x=2\\x=-1\end{cases}}\)

Vậy...

b)  \(5x\left(x-3\right)-x+3=0\)

<=>  \(\left(x-3\right)\left(5x-1\right)=0\)

<=>  \(\orbr{\begin{cases}x-3=0\\5x-1=0\end{cases}}\)

<=>  \(\orbr{\begin{cases}x=3\\x=\frac{1}{5}\end{cases}}\)

Vậy...