First, calculate the change in the total miles from year 3 to year 4 by substracting the total amount of miles in year 3 from the total amount of miles in year 4:
[tex]47,600-35,700=11,900[/tex]
Calculate the change from year 4 to 5 using a similar method:
[tex]59,500-47,600=11,900[/tex]
Notice that there is a common difference of 11,900 miles per year. This means that, if the pattern continues, on year 6 Zac will drive another 11,900 miles. Add 11.900 to the mile count of year 5 to find what the mile count for year 6 will be:
[tex]\text{Year 6}\rightarrow59,500+11,900=71,400[/tex]
Therefore, at the end of six year, Zac has driven his car 71,400 miles.
