Odpowiedź:
P=4x
Q=-2y
R=3x-2y+5
S=-2x+y-4
a. P•R-Q•S=4x(3x-2y+5)-(-2y)(-2x+y-4)=
=12x^2-8xy+20x-(4xy-2y^2+8y)=
=12x^2-8xy+20x-4xy+2y^2-8y=
=12x^2+20x-12xy+2y^2-8y
b. P•S+R•Q=4x(-2x+y-4)+(3x-2y+5)(-2y)=
=-8x^2+4xy-16x-6xy+4y^2-10y=
=-8x^2-16x-2xy+4y^2-10y
Szczegółowe wyjaśnienie:
^2 do kwadratu
