(1)12.5×0.76×0.4×8×25 (2)75×4.68+468×0.35-46.8 (3)1+2-3-4+5+6-7-8+9+10-11-12+…+2001+2002 (4)22×22×22-22×22-21 (5)(3+5+7+
问题描述:
(1)12.5×0.76×0.4×8×25
(2)75×4.68+468×0.35-46.8
(3)1+2-3-4+5+6-7-8+9+10-11-12+…+2001+2002
(4)22×22×22-22×22-21
(5)(3+5+7+9+11+…+2003)-(2+4+6+8+10+…+2002)
答
(1)12.5×0.76×0.4×8×25=(12.5×8)×0.76×(0.4×25)=100×0.76×10=760;(2)75×4.68+468×0.35-46.8=75×4.68+4.68×35-4.68×10=4.68×(75+35-10)=4.68×100=468;(3)1+2-3-4+5+6-7-8+9+10-11-12+...