Answer: fries-$3.20, burger=$5.79
Step-by-step explanation:
1. form equations for each person
2. set them up one below the other
3. solve for one unknown
4. plug in that answer into one of the equations to get the other unknown
(f=fries, b=burger)
21.18=2b+3f
29.56=4b+2f
-2(21.18=2b+3f)
29.56=4b+2f
-42.36=-4b-6f
29.56=4b+2f
-12.8=-4f
3.2=f
21.18=2b+3(3.2)
21.18=2b+9.6
-9.6 -9.6
11.58=2b
5.79=b