Chapter 4.1, Problem 4E

Let L: ${ℝ}^2\to {ℝ}^2$ be a linear operator. If
$L({(1,2)}^T)={(-2,3)}^T$
and
$L({(1,-1)}^T)={(5,2)}^T$
find the value of $L({(7,5)}^T)$ .