Zapisz w jak najprostszej postaci: (x +1)(x-2)+(x+2)(x-1) (5k+n)(k-2n)-k(4k+n) (4y+3)(y-2)-2y(4-2y) bardzo proszę o pilne rozwiązanie.? ;)

(x +1)(x-2)+(x+2)(x-1)=x²-2x+x-2+x²-x+2x-2=2x²-4 (5k+n)(k-2n)-k(4k+n)=5k²-10kn+kn-2n²-4k²-kn=k²-2n²-10kn (4y+3)(y-2)-2y(4-2y)=4y²-8y+3y-6-8y-4y²=-13y-6

(x +1)(x-2)+(x+2)(x-1)= x²-2x+x-2+x²-x+2x-2=2x²-4 (5k+n)(k-2n)-k(4k+n)=5k²-10kn+kn-2n²-4k²-kn=k²-9kn-2n² (4y+3)(y-2)-2y(4-2y)=4y²-8y+3y-6-8y-4y²=-13y-6