[m](x+1)e^{x}=(x+1)\cdot (1+x+\frac{x^2}{2!}+\frac{x^3}{3!}+...+\frac{x^{n}}{n!}+ ...)[/m]
[m](x+1)e^{x}=x cdot (1+x+\frac{x^2}{2!}+\frac{x^3}{3!}+...+\frac{x^{n}}{n!}+ ...)+(1+x+\frac{x^2}{2!}+\frac{x^3}{3!}+...+\frac{x^{n}}{n!}+ ...)[/m]
[m](x+1)e^{x}=x+x^2+\frac{x^3}{2!}+\frac{x^4}{3!}+...+\frac{x^{n+1}}{n!}+ ...)+(1+x+\frac{x^2}{2!}+\frac{x^3}{3!}+...+\frac{x^{n}}{n!}+ ...)[/m]
Приводим подобные:
[m](x+1)e^{x}=1+2x+(1+\frac{1}{2!})x^2+(\frac{1}{2!}+\frac{1}{3!})x^3+(\frac{1}{3!}+\frac{1}{4!})x^4+...(\frac{1}{(n-1)!}+\frac{1}{n!})x^{n}+(\frac{1}{n!}+\frac{1}{(n+1)!})x^{n+1} ...[/m]