Explanation:
Premier membership: $150 per year
Regular membership: $50 per year + $8 per dance
The amount of dances Ginny should attend such that becoming a premier member cost less can be found by finding how many dances will cost her $150:
The regular membership can be model by:
[tex]y=8x+50[/tex]Where x is the amount of dances per year. We want to know x when y = 150:
[tex]\begin{gathered} 150=8x+50 \\ 150-50=8x \\ x=\frac{150-50}{8}=12.5 \end{gathered}[/tex]Since x is an amount of dances it cannot be 12.5 -one can't attend to 12 and a half dance-. With x = 12.5 Ginny would spend exactly $150. If she'd attend to 12 dances she would spend less than $150 and if she'd attend to 13 dances she would spend more.
Answer:
Ginny must attend to 13 dances or more such that becoming a premier member costs less.