In the present study, the race-focused and race-reimaged framework is applied to motivational belief theory to explore factors related to Latinx high school students' enrollment into AP math and AP science. Incorporating a person-centered approach to the methods, latent profile analysis was conducted to identify the unique math and science motivational beliefs profiles of Latinx high school students as potential predictors of students' enrollment into AP math or science. Exploration of external factors, such as students' perceptions of their math and science teacher's engagement was assessed as influencing students' predicted profile placement, as well as enrollment into an AP math or science course. Results determined three distinct profile groups from the LPA, which were identified as "increased math/science motivational beliefs", "moderate math/science motivational beliefs", and "conflicted math/science motivational beliefs". Logistic regression modeling indicated that students in the increased math/science motivational beliefs group had an increased likelihood of enrolling in an AP math or AP science course compared to students in the moderate group. Results further indicated that as students' perceptions of their math teacher's engagement increased, students were 6.5 times more likely to be in the increased math/science group compared to being in the moderate group. And students were less likely to be in the conflicted group compared to the moderate group. Further, as students' perceptions of their science teacher's engagement increased, students were 6.6 times more likely to be in the increased math/science motivational beliefs group than in the moderate group. Final analyses determined that students' perceptions of their math teacher's engagement were not significant in predicting enrollment in an AP math class, though perceptions of their science teacher's engagement did predict AP science enrollment. Conclusions are discussed against the current literature and recommendations for future research are presented. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]