Hint: Which amount repeats for every item?
Answer: 2n+10
Brief Explanation: The rate is $2 per item, so 2n is the variable cost. The $10 fee is the starting amount.
Hint: Is the distance remaining increasing or decreasing?
Answer: D=-60h+500
Brief Explanation: The trip starts with 500 miles remaining. Each hour, the remaining distance decreases by 60 miles, so the rate is -60.
Hint: Separate the one-time fee from the monthly cost.
Answer: C=5m+15
Brief Explanation: The monthly rate is 5 and the starting cost is 15.
Hint: The amount of water is decreasing.
Answer: V=-2m+20
Brief Explanation: The tank begins with 20 gallons and loses 2 gallons each minute, giving a rate of -2.
Hint: What is the starting value? What repeats each week?
Answer: S=20w+100
Brief Explanation: The account starts at $100 and increases by $20 each week.
Hint: Which cost changes with the number of people?
Answer: C=50p+5
Brief Explanation: The ticket cost is $50 for every person, while parking adds one fixed $5 charge.