I’m sorry if I’m wrong but I do think your answer is X=22y^-1
#8: $900. (I found this answer by multiplying 3000 and 0.3 by the way)
#9: 160 miles. I found this answer by multiplying 80 by two, since two halves/50% make a whole or 100%.
Answer: a. 10 and 12
explanation: