Although strides have been made in promoting gender equality, there still exists a lingering gap in math achievement, where males tend to outshine females. This has piqued the interest of both scientists and society, who continue to explore the reasons behind the limited representation of women in math-intensive fields such as science, technology, engineering, and mathematics (STEM). This quantitative study investigated the influence of home resources, teachers' instructional practice, and bullying on gender disparity in math identity and agency and its impact on advanced math achievement. The study's data was derived from the 2015 12th-grade Trends in Mathematics Science Study (TIMSS), a standardized test administered to students in the United States to assess their proficiency in various subjects, including advanced mathematics. Statistical analysis was conducted using IBM SPSS software, employing MANOVA test, Pearson correlations, and Multiple Regression procedures. The research findings indicate a notable influence of gender on math identity and math agency. Specifically, male students reported higher math identity compared to their female counterparts, while both genders exhibited similar levels of math agency. Moreover, the study unveiled a robust connection between math identity, math agency, and math achievement. Factors such as home resources, math identity, and gender emerged as significant indicators of math achievement. Ultimately, when all other independent variables were kept constant, mathematics achievement was found to be higher among male students than their female counterparts. [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.]