数学题2³+4³+6³+8³+···+20³简算,快
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数学题2³+4³+6³+8³+···+20³简算,快
数学题2³+4³+6³+8³+···+20³
简算,快
数学题2³+4³+6³+8³+···+20³简算,快
∵1³+2³+...+n³=(1+2+...+n)²
∴2³+4³+6³+8³+···+20³
=2³×1³+2³×2³+2³×3³+...+2³×20³
=2³×(1+2+...+20)²
=8×210²
=44100×8
=352800
=(2³+20³)×10÷2
=(2×2×2+20×20×20)×10÷2
=8008×10÷2 =80080÷2 =40040
提一个2^3,就变成2^3(1^3+2^3+........+10^3)
=8(1+2+3+........+10)^2
=8*55*55
=24200