Thay \(x=-2\) vào ta được:
\(P\left(-2\right)+\left(-2+1\right)P\left(2\right)=-2+2\)
\(\Rightarrow P\left(-2\right)-P\left(2\right)=0\)
\(\Rightarrow P\left(-2\right)=P\left(2\right)\) (1)
Thay \(x=2\) vào ta được:
\(P\left(2\right)+\left(2+1\right)P\left(-2\right)=2+2\)
\(\Rightarrow P\left(2\right)+3P\left(-2\right)=4\) (2)
Thay (1) vào (2):
\(\Rightarrow P\left(2\right)+3P\left(2\right)=4\)
\(\Rightarrow4P\left(2\right)=4\)
\(\Rightarrow P\left(2\right)=1\)