a) Ta có: \(\left|x+5\right|\ge0\)
\(\Rightarrow A=\left|x+5\right|+6\ge6\)
Vậy \(MIN_A=6\) khi x = -5
b) Ta có: \(-\left|x+1\right|\le0\)
\(\Rightarrow B=7-\left|x+1\right|\le7\)
Vậy \(MAX_B=7\) khi x = -1
c) Ta có: \(-\left|x-5\right|\le0\)
\(\Rightarrow C=8-\left|x-5\right|\le8\)
Vậy \(MAX_C=8\) khi x = 5