а) (c-9)(c-3)-6c(3c-2)=c^2-12c+27-6c*(3c-2)=c^2-12c+27-(18c-12)*c=c^2-12c+27-(18c^2-12c)=c^2-12c+27-18c^2+12c=-17c^2-12c+27+12c=-17c^2+27
а) (c-9)(c-3)-6c(3c-2)=c^2-12c+27-6c*(3c-2)=c^2-12c+27-(18c-12)*c=c^2-12c+27-(18c^2-12c)=c^2-12c+27-18c^2+12c=-17c^2-12c+27+12c=-17c^2+27