0.4×1\2×1\2(7\3+21\4)
1*3*5+2*6*10+7*21*35分之1*2*3+2*4*6+7*14*21 =[1*2*3*(1+2*2*2+7
求比值,21:35,5/6:4/9 0.8:0.32 0.4:2/3 1/4:0.25
1+2-3+4+5-9+8+7-0+21
1*3*5+2*6*10+7*21*35分之1*2*6+2*4*6+7*14*21
找规律1,1,1,2,2,3,4,5,7,9,12,16,21
1*2*3+2*4*6+7*14*21/1*3*5+2*6*10+17*21*35=?
(1/7-1/9+1/21) /1/63+(-2)^3
1,1,2,2,3,4,5,7,9,12,16,21,等称为帕多瓦数列
(-1/63)/(1/9-2/7+2/3-4/21)怎么做?
求(-1/63)/(1/9-2/7+2/3-4/21)的答案
(1×2×3+2×4×6+4×8×12+7×14×21)÷(1×3×5+2×6×10+4×12×20+7×21×35)
计算,能简算的要简算;3*(2/3+1/12)-1/4 {1-(1/7+4/21)}\4/15