68.7-(44.6+0.375) ,5625÷75+25×32 ,(564-18×24)÷12等于几?递等式909-【36×(350÷14)】,(7×8715+3×8715)÷15 ,99×99+99 ,72×123 ,55×99?怎样简便怎么算,递等式.

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68.7-(44.6+0.375) ,5625÷75+25×32 ,(564-18×24)÷12等于几?递等式909-【36×(350÷14)】,(7×8715+3×8715)÷15 ,99×99+99 ,72×123 ,55×99?怎样简便怎么算,递等式.

68.7-(44.6+0.375) ,5625÷75+25×32 ,(564-18×24)÷12等于几?递等式909-【36×(350÷14)】,(7×8715+3×8715)÷15 ,99×99+99 ,72×123 ,55×99?怎样简便怎么算,递等式.
68.7-(44.6+0.375) ,5625÷75+25×32 ,(564-18×24)÷12等于几?递等式
909-【36×(350÷14)】,(7×8715+3×8715)÷15 ,99×99+99 ,72×123 ,55×99?怎样简便怎么算,递等式.

68.7-(44.6+0.375) ,5625÷75+25×32 ,(564-18×24)÷12等于几?递等式909-【36×(350÷14)】,(7×8715+3×8715)÷15 ,99×99+99 ,72×123 ,55×99?怎样简便怎么算,递等式.
(1)
=909-(36×350÷2÷7)
=909-(36÷2×350÷7)
=909-(18×50)
=909-900
=9
(2)
5625÷75=75=25×3
25×32+25×3=25×35=875
(3)
=564÷12-18×24÷12
=47-18×2
=47-36
=9
(4)
=68.7-44.975
=23.725
(5)
=10×8715÷15
=10×581
=5810
(6)
=99×(99+1)
=99×100
=9900
(7)
55×99
=55×(100-1)
=5500-55
=5445
(8)
72×123
=9x8x(125-2)
=9x(1000-16)
=9000-144
=8856