4o4o4o4=4 o填什么符号

1:((4 - 4) * 4) + 4 = 4
2:(4 * (4 - 4)) + 4 = 4
3:4 + ((4 - 4) * 4) = 4
4:4 + (4 * (4 - 4)) = 4
5:((4 - 4) / 4) + 4 = 4
6:4 + ((4 - 4) / 4) = 4
7:4 - ((4 - 4) * 4) = 4
8:4 - (4 * (4 - 4)) = 4
9:4 - ((4 - 4) / 4) = 4