Answer:
$12
Explanation:
times Olivia ate at the restaurant=4
let x represent the cost of the salad
tip left each time=$1.50
4×1.50
=$6
Olivia left $6 dollars tip during the 4 visits
Total amt. spent after the 4 visits=$54
$54-$6(tip)
=$48
48÷4
=12
Therefore the cost of the salad during each visit was $12
Note: Please verify the answer with others.