A snowmobile is priced at $2800. The sales tax rate is 8.25%. What is the final sale price including tax?

Having a hard time understanding this question (see attachment).

The customer price index(cpi), which measures the cost of a typical package of customer goods,was 208.8 in 2011 and 244.1 in 2016.let x=11 corresponding to the year 2011 an estimate to cpi into 2013 and 2014. assume that the data can be modeled by a straight line and the trend to continue idenfinitely.use data points to find such a line and then estimate the requested quantities

Suppose the equation ||x-a|-b|=2008 has 3 distinct real roots and a not =0. find the value of b.