Question

a) |x-1|-8=12
b) |x-2|=18-3x
c) |x-2|-18+4x=0

Answer 1

a, \(\left|x-1\right|=20\)

\(\Leftrightarrow\left[{}\begin{matrix}x-1=20\\x-1=-20\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=21\\x=-19\end{matrix}\right.\)

b, đk : x =< 18/3 

\(\Leftrightarrow\left[{}\begin{matrix}x-2=18-3x\\x-2=3x-18\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=5\\x=8\left(ktm\right)\end{matrix}\right.\)

c, <=> | x - 2 | = 18 - 4x 

đk : x =< 18/4 = 9 /2 

\(\Leftrightarrow\left[{}\begin{matrix}x-2=18-4x\\x-2=4x-18\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4\\x=\dfrac{16}{3}\left(ktm\right)\end{matrix}\right.\)

 

Answer 2

\(\left|x-1\right|-8=12\)

\(\left|x-1\right|=12+8\)

\(\left|x-1\right|=20\)

\(x-1=+-20\)

 

 

Answer 3

a)\(\left|x-1\right|-8=12\Rightarrow\left|x-1\right|=20\)

   \(\Rightarrow\left[{}\begin{matrix}x-1=20\\x-1=-20\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=21\\x=-19\end{matrix}\right.\)

b)\(\left|x-2\right|=18-3x\)

   \(\Rightarrow\left[{}\begin{matrix}x-2=18-3x\\x-2=3x-18\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}4x=20\\-2x=-16\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=5\\x=8\end{matrix}\right.\)

c)\(\left|x-2\right|-18+4x=0\)

   \(\Leftrightarrow\left|x-2\right|=18-4x\)

   Làm tương tự câu b