Elcia77
A) =(2a²-14ab-ab+7b²)(5-c)=10a²-2a²c-70ab+14abc-5ab+5abc+35b²-7b²c=10a²-2a²c-75ab+19abc+35b²-7b²c b) =(ab-a-3b+3)(c+8)=abc+8ab-ac-8a-3bc-24b+3c+24 C) =(-a+1)(c-2)(b+3)=(-ac+2a+c-2)(b+3)=-abc-3ac+2ab+6a+bc+3c-2c-6=-abc-3ac+2ab+6a+bc+c-6 d) =(zy-2z)(3x-1)(y-4)=(3xyz-zy-6xz+2z)(y-4)=3xy²z-12xyz-zy²+4yz-6xyz+24xz+2yz-8z=3xy²z-18xyz-zy²6yz+24xz
b) =(ab-a-3b+3)(c+8)=abc+8ab-ac-8a-3bc-24b+3c+24
C) =(-a+1)(c-2)(b+3)=(-ac+2a+c-2)(b+3)=-abc-3ac+2ab+6a+bc+3c-2c-6=-abc-3ac+2ab+6a+bc+c-6
d) =(zy-2z)(3x-1)(y-4)=(3xyz-zy-6xz+2z)(y-4)=3xy²z-12xyz-zy²+4yz-6xyz+24xz+2yz-8z=3xy²z-18xyz-zy²6yz+24xz