The total number of possible combinations of teams that can be formed from the eighteen students is 17,296. This can be calculated by using the formula nCr, where n is the total number of students (18) and r is the number of students in each team (9). The formula is 18C9 = 18!/(9!*9!) = 18*17*16*15*14*13*12*11*10/(9*8*7*6*5*4*3*2*1) = 17,296.
