Question

a²+2b²-(a-b)²-2ab=b² тождество

Answer 1

a²+2b²-(a-b)²-2ab=a²+2b²-a²+2ab-b²=2ab=b².

Answer 2

Спасибо!!!!

Answer 3

$a^2+2b^2-(a-b)^2-2ab=a^2+2b^2-(a^2-2ab+b^2)-2ab= \ =a^2+2b^2-a^2+2ab-b^2-2ab= b^2$