Answer:
500 items
Explanation:
plug the $320000 into C
320000=500x+70000
1. substract 70000 from both sides (always get rid of adding/substracting first)
320000=500x+70000
-70000 -70000
250000=500x
2. divide both sides by 500 (you divide both sides by whatever number is in front of x so you can isolate it)
250000/500=500x/500
500=x
there you go :D good luck and have a good day