2016-05-17 | 0
A.a3·a2=a6 B.a5+a5=a10 C.(-3a3)2=6a2D.(a3)2·a=a7
2016-05-18 | 0
2016-05-21 | 0
2016-05-25 | 0
2016-05-27 | 0
2016-05-28 | 0