1的三次方+2的三次方+3的三次方+4的三次方+5的三次方+.+99的三次方
= [1/2 * 99 *(99+1) ]^2
= [1/2 * 99 *100 ]^2
= [ 99 *50 ]^2
= 4950^2
= 24502500
2的三次方+4的三次方+6的三次方+.+98的三次方
= 8*{1的三次方+2的三次方+3的三次方+.+49的三次方
= 8* [1/2 * 49 *(49+1) ]^2
= 8*[1/2 * 49 *50 ]^2
= 8*[ 49 *25 ]^2
= 8*1225^2
= 12005000
1的三次方+3的三次方+5的三次方+.+99的三次方
=【1的三次方+2的三次方+3的三次方+4的三次方+5的三次方+.+99的三次方】-【2的三次方+4的三次方+6的三次方+.+98的三次方】
= 24502500 - 12005000
= 12497500