Answer:
Total cost =

Explanation:
We are given that Ross is shopping for mulch that costs $1.29 per cubic feet.
He bought during his first trip =16.5 cubic feet
He need another cubic feet to complete his landscaping project =4.54
We have to find an expression which shows total cost in dollars of the mulch.
Cost of 1 cubic feet =$1.29
Total number of cubic feet he bought=16. 5
Extra cubic feet =4.54
Total cubic feet he bought=4.54+16.5=21.04 cubic feet
Total cost =

Hence, the total cost $27.1416 of the mulch.