Jenny started with $5 in her piggy bank and earns an
 allowance of $2 every 3 days.
 Mika had saved $16 in his piggy bank from babysitting
 but he spends $3 a day to buy a soda on his way home
 from school.
 Let x represent the number of days that have passed and
 y represent the amount of money they have.
 When will Jenny and Mika have the same amount of
 money?