Doprowadz do najprostszej postaci: a) 2(½x-y)²-6 (⅔x+1)(⅔x-1) b) -9(⅓x-y)²-5(2/5x+y)( 2/5x-y) z gory dzieki ;) 2/5 - w ułamku .

= 2(1/4x2 - xy + y2) -6(4/9x2 -1) = 1/2x2 - 2xy + 2y2 - 8/3x2 + 6 = 1/2x2 -8/3x2 - 2xy +2y2 + 6 = 3/6x2 - 16/6x2 - 2xy + 2y2 + 6 = -13/6x2 - 2xy + 2y2 + 6 = -9 (1/9x2 - 2/3xy + y2) - 5 (4/25x2 - y2) = -x2 + 6xy - 9y2 - 4/5x2 + 5y2 = -9/5x2 - 4y2 + 6xy