2×2×2+4×4×4+6×6×6+…+98×98×98+100×100×100 简便计算~

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/07 22:47:50
2×2×2+4×4×4+6×6×6+…+98×98×98+100×100×100 简便计算~

2×2×2+4×4×4+6×6×6+…+98×98×98+100×100×100 简便计算~
2×2×2+4×4×4+6×6×6+…+98×98×98+100×100×100 简便计算~

2×2×2+4×4×4+6×6×6+…+98×98×98+100×100×100 简便计算~
2³+4³+6³……+98³+100³
=8×(1³+2³+3³+...+50³)
=8×(51×50÷2)²
=8×1625625
=13005000

2×2×2+4×4×4+6×6×6+…+98×98×98+100×100×100
=8×(1×1×1+2×2×2+3×3×3+……+49×49×49+50×50×50)
=8×(1+2+3+……+49+50)的平方
=8×【(1+50)×50/2】的平方
=8×1275的平方
=8×1625625
=13005000

原式=2^3+4^3+6^3+……+100^3
=8(1+2^3+3^3+……+50^3)
=8(50*51/2)^2
=8*1257的平方

1^3 + 2^3 + …… n^3 = [n (n+1) / 2]^2=(1+2+……+n)^2
原式=8X( 1^3 + 2^3 + …… 50^3)
= 8X[50X (50+1) / 2]^2
=8X(1+2+……+50)^2
=8X(1275)^2
=8X1625625
=13005000

2×2×2+4×4×4+6×6×6+…+98×98×98+100×100×100
=8×(1×1×1+2×2×2+3×3×3+……+49×49×49+50×50×50)
=8×(1+2+3+……+49+50)^2
=8×【(1+50)×50/2】^2
=8×1275^2
=8×1625625
=13005000