Answer:
The cost of the dinner before other costs is $14.20
Step-by-step explanation:
To solve this, we write the following equation:
x + .11x + .20x = 18.60
This is because in addition to paying for the dinner (x), she also has to pay 11% of it and another 20% of it. Now we can combine like terms and solve.
1.31x = 18.60
x = 14.20
