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Answer 1

\(\begin{cases}4x-y=5\\2\left|y-2x\right|+\left|x+y-1\right|=7\left(1\right)\end{cases}\)

\(4x-y=5\Rightarrow y=4x-5\)

Thay vào (1) ta có:

\(\left(1\right)\Leftrightarrow2\left|4x-5-2x\right|+\left|x+4x-5-1\right|=7\)

\(\Leftrightarrow2\left|2x-5\right|+\left|5x-6\right|=7\)

\(\Leftrightarrow\left|9x-16\right|=7\)

\(\Leftrightarrow9x-16=\pm7\)

Nếu \(9x-16=7\)

\(\Rightarrow9x=23\)

\(\Rightarrow x=\frac{23}{9}\)

Nếu \(9x-16=-7\)

\(\Rightarrow9x=9\)

\(\Rightarrow x=1\)