Determine if each function is linear or nonlinear.
a= linear b=non-linear

3x+y=12 a or b
y= \frac{6}{y} -2 a or b
y= \frac{x}{2} -3 a or b
y=3 x^{3} +5 a or b
y=x a or b

Juanita wade's new car has an msrp of $28,902.11 including title and processing fees. the premier package which includes surround sound and dvd player costs three times the amount of the in-style package which includes leather seats and select wheels. the total cost of her new car was $34,290.08 which included the 6.5% sales tax. find the cost of the premier package to the nearest cent.