Researchers highlight the critical role of algebraic reasoning and sense-making in developing students’ conceptual understanding of mathematics. Consequently understanding and developing pre-service teachers’ own reasoning and sense-making abilities are essential for developing students’ algebraic skills. In this presentation, we present the results of a study in which we explore pre-service teachers’ reasoning and sense-making in algebra across two distinct types of tasks: problem-solving concerning growing patterns and problem-posing tasks involving first-degree equations. The research question guiding the analysis is: Which opportunities do different tasks provide for pre-service teachers’ reasoning and sense-making, and how do pre-service teachers utilize these opportunities in their reasoning and sense-making? The studyinvolved 79 pre-service primary teachers taking a mandatory written exam as part of amathematics teacher education course. The analysis applied a qualitative/interpretative methodology, utilizing variation theory and assemblage theory as analytical frameworks (Deleuze & Guattari, 1987; Marton, 2015; Olteanu, 2022). Key analytical tools - lines of flight, segmentarity, and rupture - inform diverse connections. The study results indicate that problem-solving and problem-posing tasks offer dynamic opportunities for connecting reasoning and sense-making among pre-service teachers. This connection is characterized by essential actions in reasoning like selecting, exploring, abstracting, encoding, and connecting information, while sense-making involves recognition, relationship identification, comparison, explanation, and verification. Pre-service teachers utilize these opportunities through the interplay of lines of flight, which provide new ways for reasoning and sense-making that enable the distinction of critical aspects. While pre-service teachers connect reasoning andsense-making by segmentarity and rupture in problem-solving tasks, they do this by employing segmentarity in problem-posing tasks. Segmentarity restricts changes i npre-service teachers’ reasoning and sense-making, thus limiting the distinction of critical aspects, while rupture leads to transformation or introduces new opportunities for distinguishing critical aspects.