Question

Tìm x:

1) 4x.(x+1)-3x.(x+2)=0

2) x.(4x-2)-3x.(x-1)=x+1

Answer 1

Tìm x:

1) 4x(x + 1) - 3x(x + 2) = 0

\(\Leftrightarrow4x^2+4x-3x^2-6x=0\)

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

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

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

Vậy x ={0; 2}

2) x(4x - 2) - 3x(x - 1) = x + 1

\(\Leftrightarrow4x^2-2x-3x^2+3x=x+1\)

\(\Leftrightarrow x^2+x=x+1\)

\(\Leftrightarrow x^2-1=0\)

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

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

Vậy x={1; -1}