Đáp án:
Giải thích các bước giải:
b. $2x.(x+2)=0$
⇒\(\left[ \begin{array}{l}2x=0\\x+2=0\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=0\\x=-2\end{array} \right.\)
Vậy....
c. $1,6 - |x-0,2|=0$
$|x-0,2|=1,6$
⇒\(\left[ \begin{array}{l}x-0,2=1,6\\x-0,2=-1,6\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=1,8\\x=1,4\end{array} \right.\)
Vậy ....
d. $2.|2,5-x|-3=3$
$2.|2,5-x|=6$
$|2,5-x|=3$
⇒\(\left[ \begin{array}{l}2,5-x=3\\2,5-x=-3\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=-0,5\\x=5,5\end{array} \right.\)
