Odpowiedź:
[tex]a)\ \ (2x-3y)(4x+y)=8x^2+2xy-12xy-3y^2=8x^2-10xy-3y^2\\\\b)\ \ (2a^2-3a)(4a-5)=8a^3-10a^2-12a^2+15a=8a^3-22a^2+15a\\\\c)\ \ 2x(x+2y)-3y(4x-y)=2x^2+4xy-12xy+3y^2=2x^2-8xy+3y^2\\\\d)\ \ 2z(3w-4z)-5z(w+5z)=6wz-8z^2-5wz-25z^2=wz-33z^2[/tex]
