Let's imagine there's a block of mass m sitting on a rough surface with a kinetic friction coefficient $\mu$. It's being pulled with a constant force $A$ at $h$ degrees above the horizontal and is displaced a distance $d$. The work done by $A$ on the block is positive and is the horizontal component of $A$ times the displacement:
I thought this meant that the work done by friction would be either the negative of that amount or else
but apparently not?