In this talk, we will start by finding out where the arrows are in algebra so we can turn them all around, yielding a subject called coalgebra. Coalgebra turns out to model various forms of automata and dynamical systems. A "coequation", then, is something that controls, specifies, or constrains the behavior of such systems. We will explore the analogy of "equational logic" for algebras with "modal logic" for coalgebras. Finally, we will proceed to co-solve co-systems of co-linear co-equations and end by learning the co-quadratic formula.