两道奥数题求解

2025-01-18 20:29:29
推荐回答(5个)
回答1:

1 6*4014+9*4016+1/2 / 3*4014+3*6024+1/4
= 2x3x4014+3x3x2x2008+1/2 / 3x4014+3x3x2008+1/4
=2(3x4014+9x2008+1/4)/3x4014+9x2008+1/4
=2
2 (49-1/8)*1/8+(46-1/8)*1/8+(43-1/8)*1/8+........+(1-1/8)*1/8
= 1/8(49+46+43+...+4+1-1/8x17)(小学没有学数列,所以分开算)
=1/8{(49+1)+(46+4)+(43+7)+....(31+19)+(28+22)+25-17/8}
= 1/8(50+50+...50+25-17/8)有8个50
=1/8x425-17/64
=4983/64

回答2:

1 6*4014+9*4016+1/2 / 3*4014+3*6024+1/4
=(12×2007+18×2008+1/2)/(6×2007+9×2008+1/4)
=2
2(49-1/8)*1/8+(46-1/8)*1/8+(43-1/8)*1/8+........+(1-1/8)*1/8
=(49+16+43+……+1)×1/8-1/8×17 (共17项,(49-1)÷3+1=17)
=(49+1)×17÷2×1/8-1/8×17
=﹙25×17-17﹚×1/8
=24×17×1/8
=3×17
=51

回答3:

4016=2008*2
6024=2008*3
这样明白没。

回答4:

1.=6×4014+9×4014+18+1/2 / 3×4014+4.5×4014+9+1/4
=15×4014+18+1/2 / 7.5×4014+9+1/4
=2
2.=1/8×(49+46+43+……+1-1/8×17)
=1/8×(49+1)×17-1/8×(16+1)
=1/8×50×17-2-1/8
= 1/8×50×16-2
=98

回答5:

2.(49-1)/3+1=17项
原式=(49+46+...+1)*1/8-1/8*1/8*17
=(49+1)/2*17*1/8-1/8*1/8*17
=...