(T_(2) o T_(1))(v)=T_(2) (T_(1)v)=T_(2) (7v-7u)=7T_(2)v-7T_(2)u=
=7*(4v+5u)-7*(6v+2u)=28v+35u-42v-14u= [b]21u-14v [/b]
(T_(2) o T_(1))(u)=T_(2) (T_(1)u)=T_(2) (-7v-6u)=-7T_(2)v-6T_(2)u=
=-7*(4v+5u)-6*(6v+2u)=-28v-35u-36v-12u= [b]-64v-47u [/b]