Answer: Each dozen of chocolate chip cookies costs $1.50/dozen. So if you sell C dozens of them, you win C*$1.50 dollars, where C is a positive integer number. Similar case for the lemon ones, the baker will win L*$1.00 dollars if he sells L dozens of them ( where L is a positive integer), the total charge is the sum of both parts; T = L*$1.00 + C*$1.50.
You want to know the value of x that makes y=1000. You can plug the equation in to your calculator or desmos. Look at the table for when y=1000. X is 26.
To check, plug in 26 for x. 26^2 + 20(26) - 196 = 1000.