1/ \(\Leftrightarrow\hept{\begin{cases}x=0\\x+7=0\end{cases}}\)\(\Leftrightarrow\hept{\begin{cases}x=0\\x=0-7\end{cases}}\)\(\Leftrightarrow\hept{\begin{cases}x=0\\x=-7\end{cases}}\)

Vậy x = {0;-7}

2/ \(\Leftrightarrow\hept{\begin{cases}x+12=0\\x-3=0\end{cases}}\)\(\Leftrightarrow\hept{\begin{cases}x=0-12\\x=0+3\end{cases}}\)\(\Leftrightarrow\hept{\begin{cases}x=-12\\x=3\end{cases}}\)

Vậy x = {-12;3}

3/ \(\Leftrightarrow\hept{\begin{cases}-x+5=0\\3-x=0\end{cases}}\)\(\Leftrightarrow\hept{\begin{cases}-x=0-5\\x=3-0\end{cases}}\)\(\Leftrightarrow\hept{\begin{cases}-x=-5\\x=3\end{cases}}\)\(\Leftrightarrow\hept{\begin{cases}x=5\\x=3\end{cases}}\)

Vậy x = {3;5}

2^12

k nha

mình nhanh nhất

21nhe hom qua thi ghi vao 42 no bao sai

16.2 la dung 100% luon

song nho tk cho tao