<em>The </em><em>graph</em><em> of both modelling equations using a common </em><em>coordinate system</em><em> has been attached to this answer.</em>
<em />
From the given table, we see that;
In 1970; The sales price was;
In Seattle = $38000
In Port Townsend = $84000
In 1990; The sales price was;
In Seattle = $8400
In Port Townsend = $168400
Now, to draw a graph that will model the equations that will arise from the given table, we will make the y-axis to be the amount of sales price while the x-axis will be the year of the sales price.
The red line on the<em>attached graph </em>represents the line for Port Townsend while the blue <em>line</em> represents Seattle.
If each ticket is $9.75, then you multiply $9.75 by how many tickets he's buying. In this case he's buying 3, so it's 9.75x3. The total for that is $29.25. You subtract $28.25 from $43 and that leaves him with $13.75