13.下列运算正确的是( )
0 282944 282952 282958 282962 282968 282970 282974 282980 282982 282988 282994 282998 283000 283004 283010 283012 283018 283022 283024 283028 283030 283034 283036 283038 283039 283040 283042 283043 283044 283046 283048 283052 283054 283058 283060 283064 283070 283072 283078 283082 283084 283088 283094 283100 283102 283108 283112 283114 283120 283124 283130 283138 366461
| A. | (2a2)3=6a6 | B. | -x6÷x2=-x4 | C. | 2x+2y=4xy | D. | (x-1)2=x2-12 |