the aveawrge annual number cigarettes smoked by an adult in some countries contines to decline. For the years 1997-2006, the equation Y=-49.5+1456.1 aprozimates the data.
Here, x is the number of years after 1997 and y is the avearge annual cigarettes smoked. If this tren continues, find the year in which the average annual number of cigarettes smoked is zero.
To do this, let y=0 and solve for x. I need to round down to the neareast year. Help me understand the process.