Learning goals: Teacher Facing Comprehend that for a polynomial $p(x)$, $(x-a)$ is a factor if $p(a)=0$ and, conversely, that $p(a)=0$ if $(x-a)$ is a factor. Comprehend that for a polynomial $p(x)$ and a number $a$, the remainder on division by $(x - a)$ is $p(a)$. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from Alg2.2 Polynomials and Rational Functions, Algebra 2.