We present evidence of a secondary school teacher's Knowledge of Mathematics Teaching when she teaches linear equations in a word problem setting. We focus on analyzing the examples and mathematics support that she provides her students with during two classes. When faced with contingencies, she takes decisions whereby she adapts or creates emerging action plans in order to enrich and help her students overcome their difficulties to learn linear equations. The decisions and actions observed during the classroom practices demonstrated that providing support and examples for her students and accomplishing the lesson goals--mediated by her teaching knowledge--were at odds with each other.