Answer:
a=223.57
c=181.43
Step-by-step explanation:
a=405-c
substitute for a in the equation :
12a+5c=3590
12(405-c)+5c=3590
4860-12c+5c=3590
-7c=3590-4860
-7c=-1270
c=1270/7=181.43
a=405-1270/7
a=1565/7=223.57
