Mathematics education aims to develop and strengthen students' skills to be able to understand and address problems in their everyday lives. Components of mathematical competencies outlined in the mathematics curriculum of many countries include mathematical thinking and reasoning, problem-solving, modeling, mathematical communication, and the ability to use math tools and means of learning. One of the most significant challenges for teachers and students is to facilitate mathematical problem-solving for most students. The research was carried out to support students in developing their ability to resolve problems by teaching the first-degree equations in one unknown. The experimental study was conducted on a random sample of 82 eighth-grade students at An Thoi junior high school in Can Tho City, Vietnam. This experiment involved 82 students, 41 of whom were placed in the experimental class and the rest of whom acted as the control group. During the experiment, data were collected through study sheets, pre-test and post-test, and student interviews. Quantitative and qualitative analysis methods were applied to evaluate the results obtained and verify research hypotheses. Research results showed that most experimental class students had an improvement in the manifestation of problem-solving ability. Furthermore, it was observed that the problem-solving activities positively impacted students' positivity, initiative, creativity, and confidence in learning