Sydney subscribes to an e-book service. Her subscription costs a flat fee of $20 for up to 10 e-book downloads each month. For each download over 10 ,there is an additional charge per download. During the month of September ,Sydney downloaded 20 e-books and was charged $90. How much does each additional download cost?

$7.00

Step-by-step explanation: It says it costs $20 for up to 10 e-books downloads each month. And she downloaded 20 e-books and was charged $90. This means you need to do $90 - $20= $70. But, it wants to know the Cost of each additional download. So you would do 70 divided by 10, which equals 7.

is it 35

step-by-step explanation:

x = 3 ± √(5+y)