Odpowiedź :
[tex]a) \ 3,5(x^{2}\cdot xy -4) =3,5(x^{3}y-4) = 3,5x^{3}y - 14\\\\b) \ -6a(a-ab+b) = -6a^{2}+6a^{2}b - 6ab\\-----------------------\\\\-3x(-4y) + 5x(-2xy)+2x^{2}\cdot3y = 12xy-10x^{2}y+6x^{2}y=12xy-4x^{2}y[/tex]
[tex]a) \ 3,5(x^{2}\cdot xy -4) =3,5(x^{3}y-4) = 3,5x^{3}y - 14\\\\b) \ -6a(a-ab+b) = -6a^{2}+6a^{2}b - 6ab\\-----------------------\\\\-3x(-4y) + 5x(-2xy)+2x^{2}\cdot3y = 12xy-10x^{2}y+6x^{2}y=12xy-4x^{2}y[/tex]