The following is PreCal 11, please give me help...

Factor this:
x^2 + 4xy + 4y^2 - 4z^2

Lv beethoven software supplies customized software to a managed healthcare system. lv beethoven software's costs for the software is $1,723,000. lv beethoven software sells the software to the healthcare system for $3,816,981.10. overhead expenses are estimated at 47% of the selling price. what is lv beethoven software's net profit to the nearest dollar?

If you had $1,900,000, how many days would it take you to spend all if you spent $1 a second. (there are 86,400 seconds in a day)

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )