Answer:
1.
x=# of purple marbles
y=# of yellow marbles
y=3x
y+x=164
3x+x=164
4x=164
x=41
There are 41 purple marbles and 41*3=123 yellow marbles.
2.
L=large fries
H=hamburger
H=1.15+L
2H+L= 8.60
2.3+2L+L=8.60
2.3+3L=8.60
3L=6.3
L=2.1
A large fries costs $2,1 while a Hamburger costs 1.15+2.1=$3.25.