a) \(\left(3-x\right)\left(5x+10\right)=0\)
\(\left(3-x\right).5.\left(x+2\right)=0\)
\(\Rightarrow\orbr{\begin{cases}3-x=0\\x+2=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=3\\x=-2\end{cases}}\)
vậy...
b) \(\left|5x+2\right|-4x=7\)
\(\left|5x+2\right|=7+4x\)
\(\Rightarrow\orbr{\begin{cases}5x+2=7+4x\\5x+2=-7-4x\end{cases}}\Rightarrow\orbr{\begin{cases}5x-4x=7-2\\5x+4x=-7-2\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=5\\9x=-9\end{cases}}\Rightarrow\orbr{\begin{cases}x=5\\x=-1\end{cases}}\)
vậy....
k nha
a, \(\left(3-x\right)\left(5x+10\right)=0\)
\(\Rightarrow3-x=0\) hoặc \(5x+10=0\)
\(\Rightarrow x=3\) hoặc \(x=-2\)
\(\left|5x+2\right|-4x=7\)
\(\Rightarrow\left|5x+2\right|=7+4x\)
\(\Rightarrow\orbr{\begin{cases}5x+2=7+4x\\5x+2=-\left(7+4x\right)\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}5x-4x=7-2\\5x+2=-7-4x\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=5\\5x+4x=-7-2\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=5\\9x=-9\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=5\\x=-1\end{cases}}\)