Solutions of Indefinite Equation

Solutions of Indefinite Equation

$\sum_{i=1}^m{x_i}=x_1+x_2+\cdots+x_m=n$

• Num of positive integer solutions: $C^{m-1}_{n-1}$
• Num of nonnegative integer solutions: $C^{m-1}_{n+m-1}​$