Đáp án:
Giải thích các bước giải:
a)(-1005-x)(x+2)=0
⇔\(\left[ \begin{array}{l}-1005-x=0\\x+2=0\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=-1005\\x=-2\end{array} \right.\)
b)(8+x )(6-x)=0
⇔\(\left[ \begin{array}{l}8+x=0\\x-6=0\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=-8\\x=6\end{array} \right.\)
c)8x(5-x)=0
⇔\(\left[ \begin{array}{l}8x=0\\5-x=0\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=0\\x=5\end{array} \right.\)
d)x²-5x=0
⇔x(x-5)=0
⇔\(\left[ \begin{array}{l}x=0\\x-5=0\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=0\\x=5\end{array} \right.\)
