Answer:
$60 was the price of Zoe's dinner, before sales tax and tip.
Explanation:
1. Sales tax = 11% times original price = 0.11 times x= 0.11x
2. Tips for dinner = 20% times original price = 0.20 times x = 0.2x
3. 0.11x + 0.2x = 18.60
4. 0.31x = 18.60
5. x = 60
6. $60 was the price of Zoe's dinner, before everything else