
Answer:
30 tiles need to buy for same cost in both store.
Step-by-step explanation:
Let x be the number of tiles to buy for same cost in both store.β΄18+0.69β n=1.29β nβ΄ 1.29n β 0.69n = 18 or 0.6n =18β΄n=180.6=30 Therefore, 30 tiles need to buy for same cost in both store