The aim of this research is to obtain significant data and analyze the influence of the Team Assisted Individualization (T.A.I) learning model on the ability to solve mathematical problems on the subject of linear programming in class X students at MA Al Ittihad Sawangan Depok. The research method used is a quasi-experimental method (quasi-experiment). Sampling was carried out using a cluster random sampling technique with a research sample of 40 students, namely 20 students in class X IPS 2 as the experimental class and 20 X IPS 1 as the control class. The analysis technique used is a comparative analysis technique with the t-test, at a significance level of ?= 0,05. The analytical requirements tests used in this research are the Chi-Square test for normality test and Fisher's test for homogeneity test. At a significance level of 0,05 with the Chi-Square test in the experimental class the price X2count <X2table (-33,38 < 9,488) while for the control class the price Homogeneity test at a significance level of 0.05 with Fisher's test, obtained F-count = 1,642 and F-table = 2,165 with a significance level of ?= 0,05. Because Fcount < Ftable, H0 is accepted, so it can be concluded that the two classes have the same or homogeneous variance. Hypothesis testing uses the t-test with a significance level of ?= 0,05. From the calculation results, t-count = 3,619, while ttable with degrees of freedom = 38 is 2,026, meaning t-count > t-table. Thus H0 is rejected and H1 is accepted. This research concludes that mathematical problem solving abilities using the Team Assisted Individualization (T.A.I) learning model are better than mathematical problem solving abilities using the Expository model.