(1+3+5+7+9+...99+101)-(1+2+4...98+100)简便计算,急用,
问题描述:
(1+3+5+7+9+...99+101)-(1+2+4...98+100)简便计算,急用,
答
(1+3+5+7+9+...99+101)-(1+2+4...98+100)
=(1+101)*51÷2-1-(2+100)*50÷2
=51*51-1-51*50
=51-1
=50