a)Ta thấy: \(\left|x+1\right|\ge0\)
\(\Rightarrow-\left|x+1\right|\le0\)
\(\Rightarrow A\le0\)
Dấu "=" xảy ra khi \(-\left|x+1\right|=0\Rightarrow x+1=0\Rightarrow x=-1\)
Vậy \(Max_A=0\) khi \(x=-1\)
b)Ta thấy: \(\left|5+x\right|\ge0\)
\(\Rightarrow-\left|5+x\right|\le0\)
\(\Rightarrow A\le0\)
Dấu "=" xảy ra khi \(-\left|5+x\right|=0\Rightarrow5+x=0\Rightarrow x=-5\)
Vậy \(Max_A=0\) khi \(x=-5\)
c)Ta thấy: \(\left|x+2\right|\ge0\)
\(\Rightarrow-\left|x+2\right|\le0\)
\(\Rightarrow A\le0\)
Dấu "=" xảy ra khi \(-\left|x+2\right|=0\Rightarrow x+2=0\Rightarrow x=-2\)
d)Ta thấy: \(\left|x-3\right|\ge0\)
\(\Rightarrow-\left|x-3\right|\le0\)
\(\Rightarrow A\le0\)
Dấu "=" xảy ra khi \(-\left|x-3\right|=0\Rightarrow x-3=0\Rightarrow x=3\)
Vậy \(Max_A=0\) khi \(x=3\)
