2/25,30/16,25/39,50/36,( 448,( )60,22,8,3 1/(3*3-1)+1/(5*5-1)+1/(7*7-1)+1/(9*9-1)+1/(11*11-1)的值等于多少?
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2/25,30/16,25/39,50/36,( 448,( )60,22,8,3 1/(3*3-1)+1/(5*5-1)+1/(7*7-1)+1/(9*9-1)+1/(11*11-1)的值等于多少?
2/25,30/16,25/39,50/36,(
448,( )60,22,8,3
1/(3*3-1)+1/(5*5-1)+1/(7*7-1)+1/(9*9-1)+1/(11*11-1)的值等于多少?
2/25,30/16,25/39,50/36,( 448,( )60,22,8,3 1/(3*3-1)+1/(5*5-1)+1/(7*7-1)+1/(9*9-1)+1/(11*11-1)的值等于多少?
164
(3+8)*2=22
(8+22)*2=60
(22*60)*2=164
(60+164)*2=448
1/(3*3-1)+1/(5*5-1)+1/(7*7-1)+1/(9*9-1)+1/(11*11-1)
=1/(3-1)(3+1)+1/(5-1)(5+1)+1/(7-1)(7+1)+1/(9-1)(9+1)+1/(11-1)(11+1)
=1/2*4+1/4*6+1/6*8+1/8*10+1/10*12
=0.25*(1/1*2+1/2*3+1/3*4+1/4*5+1/5*6)
=0.25*(1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6)
=0.25*(1-1/6)
=5/24