\(P=\left(a-1\right)+|a-1|+\left(a-1\right)+|a-1|+...+|a-1|=50\left(a-1\right)+50|a-1|\)
Nếu \(a\ge1\) thì ta được:
\(P=50\left(a-1\right)+50\left(a-1\right)=100\left(a-1\right)\)
Nếu \(P< 1\) thì ta được
\(P=50\left(a-1\right)-50\left(a-1\right)=0\)