= = = == = = =
(1)﹣0.72+(﹣0.28) (2)÷[×(+)] (3)解方程:(x+7)×=1.
脱式计算,能简算的要简算.15.8﹣+﹣ ÷[(+)×] 61÷12 2+20×(﹣) 4×0.28×2.5.
简便计算.(1)625×2005+2005×38﹣2005 (2), (3).
计算下面各题:12÷25﹣23×710 ( 23﹣34×13 )÷98 13.8﹣79+6.2﹣119.
递等式计算:78×56+27×78+13×83+83×9 .