直接写出得数。(每小题0.5分,共计6分) += += 1-= -= -= -= ++1= ++= + = - = 1--= +-=
×9+12×
42:=x:
x-x=
(2.4×1.5-1.5)÷0.7
(3.2+3.2+3.2+3.2) ×2.5