计算: 2 cos 60 ° + ( - 1 ) 2017 + | - 3 | - ( 2 - 1 ) 0 .
11+192+193+19994+199995=
=
解下列方程或比例(每题3分,共12分) (1):=:x (2)= (3)2x﹣=0.5 (4)x+x=