99999×22222+33333×3334= 57+61+65+·······+1093= 巧算,并写出过程.就是99999×22222+33333×3334=的巧算和57+61+65+···········1093=的巧算OK?
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![99999×22222+33333×3334= 57+61+65+·······+1093= 巧算,并写出过程.就是99999×22222+33333×3334=的巧算和57+61+65+···········1093=的巧算OK?](/uploads/image/z/10488000-48-0.jpg?t=99999%C3%9722222%2B33333%C3%973334%3D+57%2B61%2B65%2B%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%2B1093%3D+%E5%B7%A7%E7%AE%97%2C%E5%B9%B6%E5%86%99%E5%87%BA%E8%BF%87%E7%A8%8B.%E5%B0%B1%E6%98%AF99999%C3%9722222%2B33333%C3%973334%3D%E7%9A%84%E5%B7%A7%E7%AE%97%E5%92%8C57%2B61%2B65%2B%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%C2%B7%C2%B71093%3D%E7%9A%84%E5%B7%A7%E7%AE%97OK%3F)
99999×22222+33333×3334= 57+61+65+·······+1093= 巧算,并写出过程.就是99999×22222+33333×3334=的巧算和57+61+65+···········1093=的巧算OK?
99999×22222+33333×3334= 57+61+65+·······+1093= 巧算,并写出过程.
就是99999×22222+33333×3334=的巧算和57+61+65+···········1093=的巧算
OK?
99999×22222+33333×3334= 57+61+65+·······+1093= 巧算,并写出过程.就是99999×22222+33333×3334=的巧算和57+61+65+···········1093=的巧算OK?
先算出57+61+65+···········1093共有260项,即共有260个数字相加.
设a1=57,a260=1093
那么,S260={260*(57+1093)*4}/2
=260*1050*2
=546000
99999×22222+33333×3334
=33333×3×22222+33333×3334
=33333×(66666+3334)
=33333×70000
=2333310000
99999×22222+33333×3334=
=33333*3*66666÷3+33333*3334
=33333*66666+33333*3334
=33333*(66666+3334)
=33333*70000
=2333310000
57+61+65+···········1093=
项数(1093-57)/4+1=160
(1093+57)*160/2=92000
不懂