1.(1.3×3.9×11.7+3×9×27+1/17×3/17×9/17)/(1.3×2.6×3.9+3×6×9+1/
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/10/05 00:59:01
1.(1.3×3.9×11.7+3×9×27+1/17×3/17×9/17)/(1.3×2.6×3.9+3×6×9+1/17×2/17×3/17)
2.2/3+2/9+2/27+2/81+2/243
3.1+2+3+4+5+6+7+8+9+8+7+6+5+4+3+2+1/999999999²
4.2×3×4×5+5×6×7×8/2×3×4×5
5.(1+1/2+1/3+1/4)×(1/2+1/3+1/4+1/5)-(1+1/2+1/2+1/4+1/5)×(1/2+1/3+1/4)
2.2/3+2/9+2/27+2/81+2/243
3.1+2+3+4+5+6+7+8+9+8+7+6+5+4+3+2+1/999999999²
4.2×3×4×5+5×6×7×8/2×3×4×5
5.(1+1/2+1/3+1/4)×(1/2+1/3+1/4+1/5)-(1+1/2+1/2+1/4+1/5)×(1/2+1/3+1/4)
1.(1.3×3.9×11.7+3×9×27+1/17×3/17×9/17)/(1.3×2.6×3.9+3×6×9+1/17×2/17×3/17)
=[1.3×(1+3+9)+3×(1+3+9)+1/17 ×(1+3+9)]/[1.3×(1+2+3)+3×(1+2+3)+1/17 ×(1+2+3)]
=(1.3+3+1/17)(1+3+9)/(1.3+3+1/17)(1+2+3)
=(1+3+9)/(1+2+3)
=13/6
2.2/3+2/9+2/27+2/81+2/243
=2/243 ×(81+27+9+3+1)
=2/243 × 121
=242/243
4.2×3×4×5+5×6×7×8/2×3×4×5
=120+14
=134
5.(1+1/2+1/3+1/4)×(1/2+1/3+1/4+1/5)-(1+1/2+1/3+1/4+1/5)×(1/2+1/3+1/4)
设1/2+1/3+1/4=t
原式可化为
(1+t)(t+1/5)-(1+t+1/5)t
=1/5
=[1.3×(1+3+9)+3×(1+3+9)+1/17 ×(1+3+9)]/[1.3×(1+2+3)+3×(1+2+3)+1/17 ×(1+2+3)]
=(1.3+3+1/17)(1+3+9)/(1.3+3+1/17)(1+2+3)
=(1+3+9)/(1+2+3)
=13/6
2.2/3+2/9+2/27+2/81+2/243
=2/243 ×(81+27+9+3+1)
=2/243 × 121
=242/243
4.2×3×4×5+5×6×7×8/2×3×4×5
=120+14
=134
5.(1+1/2+1/3+1/4)×(1/2+1/3+1/4+1/5)-(1+1/2+1/3+1/4+1/5)×(1/2+1/3+1/4)
设1/2+1/3+1/4=t
原式可化为
(1+t)(t+1/5)-(1+t+1/5)t
=1/5
1+2+3+4+5+6+7+8+9+10+11+12+13+14+15+16+17+18+19+20 =
(1×3×11+2×6×22+3×9×33)/ 1×2×17+2×4×34+3×6×51
数列1,3+5+7,9+11+13+15+17,19+21+23+…+29+31,…的第20项的和为( ).
已知1+2+3+...+31+32+33=17×33,求1-3+2-6+3-9+4-12+...+31-93+32-96
简算(17/25×3/50)×30/51×125 4/9×4+2/9×2+1/9×2
1+2+3+4+5+6+7+8+9+10+11+12=?
已知1+2+3+4+5+...+31+32+33=17×33,求1-3+2-6+3-9=4-12+...+31-93+3
计算1×2×4+2×4×8+3×6×12+…/1×3×9+2×6×18+3×9×27﹢…
(1/2×3)+(2/3×5)+(3/5×8)+(4/8×12)+(5/12×17)+(6/17×23)+(7/23×3
(1×6×9+2×12×18+3×18×27+.+100×600×900) /
1+2-3+4+5-6+7+8-9+.+58+56-60等于几?
1/1×3+1/3×5+1/5×7+…+1/17×19+1/9×21=?