下列计算正确的是( )
A:2a+3b=5ab
B:(﹣a2)3=a6
C:(a+b)2=a2+b2
D:8−22=0
Our government has tried many ways to the smog(雾霾)problem. Maybe we'll have a clear sky in the near future.
把下列各式填在相应的大括号里:
x﹣7,13x,4ab,23a,5﹣3x,y,st,x+13,x7+y7,x2+x2+1,m-1m+1,8a3x,﹣1
单项式集合{____ …};
多项式集合{ ____ …};
整式集合{____ …}.
科学探究的一般过程,大致可分为①____,②作出与问题有关的推测或猜想,③制定解决问题的方案,④____ ,⑤分析结果、得出结论,⑥反思、评价过程等6个环节.