问题:
(1)计算:(1-2+3-4+5-6+…+999-1000)+2000;
(2)计算: (
1×2×4+2×4×8+…+n×2n×4n
1×3×9+2×6×18+…+n×3n×9n
)2.
(1)计算:(1-2+3-4+5-6+…+999-1000)+2000;
(2)计算: (
)2.
(2)计算: (
1×2×4+2×4×8+…+n×2n×4n |
1×3×9+2×6×18+…+n×3n×9n |
参考答案: