The cost of 6 sandwiches and 4 drinks is $53. The cost of 4 sandwiches and 6 drinks is $47 how much does one sandwich cost

let sandwiches and drinks be s and d resp so according to the question,
by 1st case,
6s + 4d = 53
or, d = (53-6s)/4
again by 2nd case,
4s + 6 d = 47
4s + 6(53-6s)/4 = 47
or, (8s +159-18s)/2=47
or 159-10s = 94
or 65 =10s
or, s = $6.5