计算
=
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=
计算下面各题,能简算的要简算(每题3分,共18分) (1)884÷34+17×21 (2)1.25×3.2×0.25 (3)()÷+ (4)4÷5+39× (5)4.2﹣1.38+5.8﹣4.62 (6)2÷﹣÷2.