题目 下列运算正确的是((( ))) A.3a+2a=5a23a+2a=5a^{2}3a+2a=5a2B.3a+3b=3ab3a+3b=3ab3a+3b=3abC.2a2bc−a2bc=a2bc2a^{2}bc-a^{2}bc=a^{2}bc2a2bc−a2bc=a2bcD.a5−a2=a3a^{5}-a^{2}=a^{3}a5−a2=a3知识点：合并同类项章节：未标注
