482+532+622=?

1 Answer
Dec 25, 2015

8957

Explanation:

Use (a±b)2=a2±2ab+b2

482=(502)2=5022(50)(2)+22

=2500200+4=2304

532=(50+3)2=502+2(50)(3)+32

=2500+300+9=2809

622=(50+12)2=502+2(50)(12)+122

=2500+1200+144=3844

So:

482+532+622=2304+2809+3844=8957