(v-1)(v+2)-(v+7)^3=v^2+2v-v-2-(v^3+21v^2+147v+343)=
=v^2+2v-v-2-v^3-21v^2-147v-343=-v^3-20v^2-146v-345
(v-1)(v+2)-(v+7)^3=v^2+2v-v-2-(v^3+21v^2+147v+343)=
=v^2+2v-v-2-v^3-21v^2-147v-343=-v^3-20v^2-146v-345