(1)计算:(1-2+3-4+5-6+…+999-1000)+2000; (2)计算:(
|
(1)原式=-1×500+2000=-500+2000=1500;
(2)原式=[
]2=(8(1+8+…+n3) 27(1+8+…+n3)
)2=8 27
.64 729
(1)计算:(1-2+3-4+5-6+…+999-1000)+2000; (2)计算:(
|
(1)原式=-1×500+2000=-500+2000=1500;
(2)原式=[
]2=(8(1+8+…+n3) 27(1+8+…+n3)
)2=8 27
.64 729