2 25=15^2=15X15
6 25=25^2=25X25
42 25=65^2=65X65
大家發唔發現到...除左後面必定25之外...例如..65X65..張個6乘6...+6..=42 ...後面為25 =4225
75X75..張個7乘7...+7=56 ...後面為25 =5625

只要個數既個位係5既2次...必定係25...所以 (x乘10+5)^2=100/1000/10000/以上(x乘x+x)+25...<<應該係甘掛... (1x10+5)^2=100(1x1+1)+25
(6x10+5)^2=1000(6x6+6)+25
點睇係100定1000.甚至以上...我又發現到少少野...15x15...1x1+5=6唔過10..所以乘 100..結果=225 right
25x25...2x2+5=9唔過10..所以乘 100..結果=625 right
35x35...3x3+5=14過10..唔過100.. 所以乘 1000..結果=1225 right
45X45...4X4+5=19過10..唔過100.. 所以乘 1000..結果=2025 right
.....................................................................................................................................................
75x75...7x7+5=54過10..唔過100..所以乘1000..結果=5625 right
若上萬既數...eg.105x105..=11025

....10x10+5=105過100.所以就會乘10000
↑..岩唔岩我唔知..因為我自己發現出來- -
[
本帖最後由 .mL 於 2012-1-20 23:32 編輯 ]