Answer:
m = -1/2
Step-by-step explanation:
If you have any questions about the way I solved it, don't hesitate to ask me in the comments below =)
Pretty sure the distance is 8 units
He saves $200 (the amount of change over the original amount $500
200/500 = 2/5 and 2/5 = 40% (divide 2 by 5 and get .4 which = 40%)
40% discount is the answer to your question