u = <-3,4> a = <-13,6> v = <4,6> b = <6,-8>
T(3u + v) = T(3u) + T(v)
= 3T(u) + T(v) = 3<-13, 6> + <6, -8>
= <-39, 18> + <6, -8>
= <-33, 10>