Answer:
$128.45
Step-by-step explanation:
The computation of the combined purchase is shown below:
= Price paid by Riya + price paid by her friend
where,
Price paid by Riya is $28.50
And, the price paid by her friend equal
= Each book price × number of books
= $19.99 × 5 books
= $99.95
Now put these values to the above formula
So, the value would be equal to
= $28.50 + $99.95
= $128.45