Wykonaj dziłania i zredukuj wyrazy podobne w wyrazeniu W=(2x-y)2-(2x+y)2-(4x-3y)(4x+3y)+12x2y+y3+20x2+4xy a naspnie oblicz wartosc tego wyrazenia x=pierwiastek 5 y=-2pierwiastek5

(2x-y)2-(2x+y)2-(4x-3y)(4x+3y)+12x2y+y3+20x2+4xy= 4x^2-4xy+y^2-(4x^2+4xy+y^2)-(16x^2-9y^2)+12x^2y+y^3+20x^2+4xy= 4x^2-4xy+y^2-4x^2-4xy-y^2-16x^2+9y^2+12x^2y+y^3+20x^2+4xy= 4x^2-4xy+9y^2+12x^2y+y^3 Dowód: http://www.wolframalpha.com/input/?i=%282x-y%29%5E2-%282x%2By%29%5E2-%284x-3y%29%284x%2B3y%29%2B12x%5E2+%2Ay%2By%5E3%2B20x%5E2%2B4xy%3D p oznaczało będzie pierwiastek 4(p(5))^2-4p(5)(-2p(5))+9(-2p(5))^2+12(p(5))^2(-2p(5))+(-2p(5))^3= 20+40+180-120p(5)-40p(5)= 240-160p(5) Dowód http://www.wolframalpha.com/input/?i=4+%2Asqrt%285%29%5E2+-+4+%2Asqrt%285%29%2A%28-2%2Asqrt%285%29%29+%2B+12+%2Asqrt%285%29%5E2+%2A%28-2%2Asqrt%285%29%29+%2B+9%2A%28-2%2Asqrt%285%29%29%5E2+%2B+%28-2%2Asqrt%285%29%29%5E3