Answer:
Step-by-step explanation:
5s + 6c = 23.91
2s + 7c = 17.89
10s + 12c = 47.82
-10s - 35c = -89.45
-23c = -41.63
c = $1.81 for a large coffee
2s + 7(1.81) = 17.89
2s = 5.22
s = $2.61 for a scone
4,7,10,13,16,19,21
add 3 to every number