# covariance matrix derivation

How to derive from the first step to the second step, where y is k by 1 vector and A is k by p matrix. Thanks for any help in advance

$$(Ay - A\mu)^\top = (Ay)^\top - (A\mu)^\top = y^\top A^\top - \mu^\top A^\top = (y^\top - \mu^\top)A^\top =(y - \mu)^\top A^\top$$