Harvard University Entrance Exam Tricks | a^2-b^2=21

[@Penndennis]

Great lesson as usual. Thank you!

[@allinone-fj3yu]

Very easy

[@superacademy247]

Thanks for your input 👍Try it!

[@ganeshdas3174]

For natural number solution
a = 5 & b = 2

[@НеллиПшено]

Решаем методом устного счета.
25-4=21
a=5 b=2;
a=-5 b=-2;
a=-5 b=2;
a=5 b=-2.
Good luck!