(1)(2×3×4×5)(1/2-1/3-1/4-1/5) 通分
=(2×3×4×5)[(3×4×5-2×4×5-2×3×5-2×3×4)/(2×3×4×5)
=3×4×5-2×4×5-2×3×5-2×3×4
=60-40-30-24
=-34
(2)7778×9999+3333×6666
= 7778×9999+3333×3×2222 提取公共的因式
=9999×(7778+2222)
=9999×10000
=9.999×10^7
(3)0.125^4×8^5-0.25^10×4^9 将0.125×8,0.25×4合在一起
=(0.125×8)^4 ×8-(0.24×4)^9 ×0.25
= 1^4 ×8-1^9 ×0.25
=8-0.25
=7.75