Starlin's goal is to spend less than $415 on a trip. So far, he has spent $25 on gas for his car. He will spend $100 each day on other expenses. Let d represent the number of days for Starlin's trip.

Starlin's trip must last fewer than __ days.

Answer

Less than or equal to 4 days.

Step-by-step explanation:

Let D represent the number of days for Starlin's trip.  We know that Starlin has spent $25 on gas and will spend $100 for each day. So use the equation d=25+100d < 415. (We also know that Starlin plans on spending less than $415 on the trip, so if anything is above $415, we know it is the wrong answer.) Subtract 25 on both sides and then divide by 100; the equation should go like this:

25 + 100d < 415

25 + 100d - 25 < 415 - 25

100d < 390

d < 3.9

It would be wise to round to 4 unless otherwise specified.