One daylily $10 and 1 shrub $11
1) Gathering the data from the question
Erica spent $200 on 9 daylillies and 10 shrubs
Megan spent $185 on 13 daylilies and 5 shrubs
9d+10s=200
13d+5s=185
2) Let's solve this system of linear equations now
9d+10s=200
13d+5s=185 Multiply by (-2)
9d +10s=200
-26d-10=-370
----------------------
-17d =-170
17d=170
d=10
9(10) +10s=200
90+10s-90=200-90
10s=200-90
10s=110
s=11
So the cost of one daylily is$10 and 1 shrub is $11