Спростити: (2a-3b) ^2 - (3a+2b) ^2;

(2x-3y) ^2 + (4x+2y) ^2

1) (2 а-3b) ² - (3a+2b) ² = (2a) ²-2*2a*3b + (3b) ² - ((3a) ²+2*3a*2b + (2b) ²) =

=4a²+12ab+9b²-9a²-12ab-4b² = (4a²-9a²) + (12ab-12ab) + (9b²-4b²) =

=-5a²+5b² = 5 * (b²-a²)

2) (2x-3y) ² + (4x+2y) ² = (4x²-2*2x*3y+9y²) + (16x²+2*4x*2y+4y²) =

= (4x²+16x²) + (-12xy+16xy) + (9y²+4y²) = 20x²+4xy+13y²