а) 2,5a2b(4a2-2ab+0,2b2)=5ab(8a-2ab+0,4b)=40a^2b-10a^2b^2+2ab^2
б)(a2-2a+3) (a-4)=a*2(a-4)-2a*(a-4)+3(a-4)=2a^2-8a-2a^2+8a+3a-12=3a-12
в)(3y-4) (y2-y+1)=3y*(y*2-y+1)-4(y*2-y+1)=6y^2-3y^2+3y-8y+4y-4=3y^2-y-4
а) 2,5a2b(4a2-2ab+0,2b2)=5ab(8a-2ab+0,4b)=40a^2b-10a^2b^2+2ab^2
б)(a2-2a+3) (a-4)=a*2(a-4)-2a*(a-4)+3(a-4)=2a^2-8a-2a^2+8a+3a-12=3a-12
в)(3y-4) (y2-y+1)=3y*(y*2-y+1)-4(y*2-y+1)=6y^2-3y^2+3y-8y+4y-4=3y^2-y-4