Đáp án:
a, `2x - 4y = 0`
`<=> 2(x - 2y) = 0`
`<=> x - 2y = 0`
`<=> x = 2y`
b, `x^3 - 4x^2 + 4x = 0`
`<=> x(x^2 - 4x + 4) = 0`
`<=> x(x - 2)^2 = 0`
<=> \(\left[ \begin{array}{l}x=0\\x - 2 = 0\end{array} \right.\)
<=> \(\left[ \begin{array}{l}x=0\\x=2\end{array} \right.\)
c, `x^2 - 6x - xy + 6y = 0`
`<=> x(x - 6) - y(x - 6) = 0`
`<=> (x - y)(x - 6) = 0`
<=> \(\left[ \begin{array}{l}x - y = 0\\x - 6 = 0\end{array} \right.\)
<=> \(\left[ \begin{array}{l}x=y\\x=6\end{array} \right.\)
d, `3x(x + 4) = 0`
<=> \(\left[ \begin{array}{l}x=0\\x + 4 = 0\end{array} \right.\)
<=> \(\left[ \begin{array}{l}x=0\\x=-4\end{array} \right.\)
Giải thích các bước giải:
