如图,正方形ABCD的边CD在正方形ECGF的边CE上,O是EG的中点,∠EGC的平分线GH过点D,交BE于点H,连接OH,FH,EG与FH交于点M,对于下面四个结论:①GH⊥BE;②HOBG;③S正方形ABCD:S正方形ECGF=1:;④EM:MG=1:(),其中正确结论的序号为 .
(1)当x_______时,=-2有意义; (2)当x_______时,(x+5)0=1有意义; (3)当x_______时,(x+5)-2=1有意义.
计算: (1)-0.10=________;(2)(-0.1)0=_______; (3)(-0.5)-2=_______; (4)(-)-1=________.
a0=______(a≠0);a-p=_______(a≠0,p是正整数).
代数式的意义为___________.
计算: (1)199.92=_______;(2)512=________;(3)1-2×51+512=_______.