x = # of ham sandwiches
14-x = # of turkey sandwiches ( as Lexi made 14 sandwiches)
as the question said that the number of ha sandwiches are 4 less than twice number of turkey sandwiches,
x = 2 * (14-x) - 4 = 24 - 2x
3x=24
x = 8
the number of ham sandwiches is 8, and the number of turkey sandwiches is 14-8=6