一位数加减混合(3个数)

9 + 4 - 4 = 9 + 7 + 5 = 1 + 6 - 5 = 1 + 9 - 10 = 6 + 5 - 8 = 7 - 1 + 3 = 5 - 3 + 3 = 10 - 8 + 6 = 1