So this problem is asking you to plug numbers in for t. 0 1 2 3 4 5. So your first equation would be 2× 0+8 and you would get 8 so for 0 toppings you would pay 8 dollars then graph this over 0 up 8. Next equation 2×1+8 is 10. Graph. over 1 up 10. Next 2×2+8 is 12. Graph. Over 2 up 12. next 2× 3 + 8 is 14. Graph. Over 3 up 14. Next 2×4+8 is 16 so over 4 up 16. Last 2×5+8 is 18 so over 5 up 18. Your Y-intercept is the dot that is on the y axis and in this problem that is 8. This means if you buy 0 toppings you will spend 8 dollars.
Let the average cost of car in 2009 be $x, then the average cost of a car in 2013 is 2x - 5 25,000 = 2x - 5 2x = 25,000 + 5 = 25,005 x = 25,005/2 = $12,502.50
