What is the generating function for the sequence an=5na_n = 5^nan=5n?
A(x)=11−5xA(x) = \frac{1}{1-5x}A(x)=1−5x1
A(x)=11+5xA(x) = \frac{1}{1+5x}A(x)=1+5x1
A(x)=51−xA(x) = \frac{5}{1-x}A(x)=1−x5
A(x)=15−xA(x) = \frac{1}{5-x}A(x)=5−x1