∴3a+2=29,
解得a=9,
∴a2+2a+1=92+2×9
、某物体经凸透镜在光屏上得到一个像, 现将透镜上部遮住不让光通过,则屏上的像( )
若|x|=1,|y|=4,且xy<0,则x﹣y的值等于( )
Officials from China and France formally promised on Thursday to build a new type of economic partnership, while ________ business cooperation.
有一包粉末,已知其由BaCO3、Cu(NO3)2、Na2SO4、NaCl、NaOH中的几种组成,现对其做以下实验,各步骤均已经充分反应,请回答问题:
When we were in Anhui, we took many photos ________ Mount Huang.