Martin is saving money to buy a new phone that costs $1,000 by selling trees. He is using an app to manage his sales, but it keeps a fraction of each sale. His net pay is modeled by the function P(x) = x2 + 20x – 196, where x represents the number of sales. How many sales does Martin need to make to earn $1,000?

10 sales
26 sales
46 sales
1296 sales