The answer is ( x - 3 ) ( x - 5)
I think it’s 12, if you take $360 and subtract the $120 deposit you get 240 and i divided that by 20 to get 12.
3449995000 is what I got, I did 3.45x10^9 and then used that number and subtracted the answer from 0.5x10^4 to get the final answer, if that makes any sense.