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1. Ute Hauth (miradlo@pirati.ca)'s status on Sunday, 29-Apr-2018 18:06:43 UTC Ute Hauth
   ♲ @Vincent Pantal🍩ni (panlepan@twitter.com): (a+b)²=a²+2ab+b²
   
   pbs.twimg.com/media/Db5JE_9WsA…
   
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   • СтаЛьг (staleg@loadaverage.org)'s status on Sunday, 29-Apr-2018 19:06:37 UTC СтаЛьг

     in reply to
     @miradlo since that, it equals to a²+b(2a+b) (the core formula for manual sqrt method, if anyone remembers it).
     …
     Moreover, if the first number can be assigned as 10a, and b=5, we'd got:
     (10a+b)² = 100a²+20a•5+25=100a(a+1)+25.
     Hence, to square any [two-digit] number ending by 5, you should multiply number of tens with one added with 1, and write 25 after that. So, 75²={7·8=56}= 5625.
     …
     Enjoy! 😜
     #mathhack
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