求解!这些简便算式怎么做?能简算的要用简便方法计算。(x是乘号) (1)93x3/92 (2)1/4x32x5/6x4/7 (3)1/8x24x2/3x3/8 (4)18x(5/6-2/9) (5)4/5x3+6x4/5+4/5 (6)1/5x1/5x3又1/20x25 (7)13x17/5x1/13x5/11 (8)28x25 (9)3/37x20x37/60 (10)901x2/53 (11)268x3/27
第1个回答 2020-03-03
(1)93x3/92=(92+1)x3/92=92x3/92+1x3/92=279/92(活用分配律) (2)1/4x32x5/6x4/7 =16x5/3x1/7=80/21(约分) (3)1/8x24x2/3x3/8 =3/4(直接约分) (4)18x(5/6-2/9)=18x5/6-18x2/9=15-4=11(分配律)(5)4/5x3+6x4/5+4/5=4/5x(3+6+1)=8(同上,倒用) (6)1/5x1/5x3又1/20x25=3又1/20(约分) (7)13x17/5x1/13x5/11=17/11(约分) (8)28x25=(30-2)x25=750-50=700(活用) (9)3/37x20x37/60=1(约分) (10)901x2/53=53x17x2/53=34(不解释) (11)268x3/27=268/9(题目有问题) 谁出的题啊,没水平。。。都很简单,要掌握做题的方法。。。