Number of positive integral solutions of x1 x2 x3 x4 20 July 8, 2019 16 32 64 128 X1 + x2 + x3 = 20 each xi is a positive integer Find the number of integer solutions to x1+x2+x3+x4=21 Find the number of integer solutions to x1+x2+x3+x4=20
