a) Let $T: \mathbb{R}^2 \rightarrow\mathbb{R}^2$ be a linear transformation such that $T(1,1) = (1,2)$ and $T(1,2)=(3,4)$. Find $T(5,8)$ and $T(3,-2)$ ?

b) Let $T: \mathbb{R}^3 \rightarrow\mathbb{R}^2$ be a linear transformation such that $T(1,0,-1) = (2,3)$ and $T(2,1,3) = (-1,0)$. Find $T(8,3,7)$?