Question

(85.12÷2.8+2.8)×25.怎样简便计算？

Answer 1

(85.12÷2.8+2.8)×25
=(85.12÷0.4÷7+2.8)×25
=(212.8÷7+2.8)×25
=(30.4+2.8)×25
=30.4×25+2.8×25
=751+70=821
简便方法一将除2.8分为除以0.4除以0.8，乘法结合律，二将25分别乘以括号里的数，乘法分配率。

Answer 2

25需要一个4
=(85.12+1)÷2.8×25
=86.12÷2.8×25
=21.53×4÷2.8×25
=21.53÷2.8×100
≈768.9285714

Answer 3

(85.12÷2.8+2.8)x25怎么简便计算？(85.12÷2.8+2.8)x25=((84+1.12)÷2.8+2.8)x25=(84÷2.8+1.12÷2.8+2.8)x25=(30+0.4+2.8)x25=33.2x25=33.2x4x25÷4=33.2x100÷4=3320÷4=830

Answer 4

答：（85.12÷2.8+2.8）*25
=85.12*25÷2.8+2.8*25
=21.28*4*25÷2.8+4*0.7*25
=2128÷2.8+70
=304÷0.4+70
=760+70
=830
所以答案是830。

Answer 5

(85.12÷2.8+2.8)×25
=(21.28÷0.7+2.8)ⅹ25
=(30.4+2.8)ⅹ25
=(32+1.2)x25
=(8+0.3)x25ⅹ4
=8.3ⅹ100
=830