y = 5x + 30
does not fit
does not fit
does not fit

Admission to an amusement park costs $30, and ride tickets cost $5 each. Michelle pays a total of y dollars to ride x rides.

Barney’s weekly lunch budget is $30. The cafeteria in his office building sells lunches for $5 each. After x days, Barney will have y dollars remaining in his budget.

Miranda has $30 in her savings account. Each week, she contributes $5. After x weeks, she will have y dollars in her savings account.

Incorrect. The fixed cost here is $30 and the cost per ticket is $5.

Correct! The rate in this situation is decreasing, but the coefficient of x is positive.

Incorrect. The initial amount in this situation is $30 and the rate of savings is $5 per week.