三个数相加的和都等于八

这个问题可以通过列出方程来解决。设这三个数分别为a、b、c，那么根据题目条件，我们可以得到以下三个方程：

1. a + b + c = 8

2. a + b + c = 8

3. a + b + c = 8

由于三个方程都是相同的，我们可以看出任意两个数的组合相加都可以得到第三个数。例如：

如果a + b = 8，那么c = 8 (a + b) = 0

如果a + c = 8，那么b = 8 (a + c) = 0

如果b + c = 8，那么a = 8 (b + c) = 0

因此，三个数可以是任意两个数相加等于8，第三个数为0。以下是一些可能的组合：

a = 2, b = 3, c = 3

a = 1, b = 4, c = 3

a = 0, b = 5, c = 3

a = 0, b = 4, c = 4

a = 1, b = 3, c = 4

a = 2, b = 2, c = 4

a = 3, b = 1, c = 4

a = 3, b = 0, c = 5

a = 2, b = 1, c = 5

a = 1, b = 2, c = 5

a = 0, b = 3, c = 5

a = 0, b = 2, c = 6

a = 1, b = 1, c = 6

a = 2, b = 0, c = 6

a = 3, b = 0, c = 5

a = 4, b = 0, c = 4

a = 5, b = 0, c = 3

a = 6, b = 0, c = 2

a = 7, b = 0, c = 1

a = 8, b = 0, c = 0

这些只是所有可能组合中的一小部分。实际上，只要满足两个数的和等于第三个数，并且三个数的总和为8，就可以有无数种组合。