vector{p}*vector{q}=(vector{a}-2*vector{b})*(2*vector{a}+vector{b})=
=vector{a}*2*vector{a}-2*vector{b}*2*vector{a}+ vector{a}*vector{b}-2*vector{b}*vector{b}=
=2*vector{a}*vector{a}-3*vector{a}*vector{b}-2*vector{b}*vector{b}=
=2*(2*2+(-5)*(-5)+(-7)*(-7))-3*(2*5+(-5)*2+(-7)*(-5))-2*(5*5+2*2+(-5)*(-5))=