Question

Giá trị của y, biết: lx -y + 5l + lx - 1l =0

Answer 1

Vì \(\left|x-y+5\right|\ge0;\left|x-1\right|\ge0\)

\(\Rightarrow\left|x-y+5\right|+\left|x-1\right|\ge0\)

Dấu "=" xảy ra <=> \(\hept{\begin{cases}\left|x-y+5\right|=0\\\left|x-1\right|=0\end{cases}\Leftrightarrow\hept{\begin{cases}x-y+5=0\\x-1=0\end{cases}\Rightarrow}\hept{\begin{cases}x-y=-5\\x=1\end{cases}\Rightarrow}\hept{\begin{cases}x=1\\y=6\end{cases}}}\)

Vậy x = 1; y = 6

Answer 2

|x-y+5|=0=>x-y+5=0

<=>|x-1|=0=>x-1=0

=>x=1

=>y=1-y+5=0=>1-y=-5=>y=-5-1=-6