Answer:
There are 210 students who run track and 98 students who play baseball. 
Step-by-step explanation:
15x= Students who run track 
7x= Students who play baseball 
15x - 7x = 112 (*combine like terms)
8x = 112 (*divide 112 by 8)
X = 14 (*now plug X into both equations stated earlier) 
15x = 15 x 14 = 210 (Number of students who run track 
7x = 7 x 14 = 98 (Number of students who play baseball)