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Interpret Equations

  1. $p$, which represents the average cost of the paper, will go up if the cost of the her favorite paper goes up.
  2. $b$, which represents the number of boxes that she wraps, will go up in the holiday season.
  3. 4 is multiplied by $hl$, which represent "height x length," so, the four must represent the 4 sides of the box.
  4. $hl$ (height times length) is multiplied by 4 and $lw$ (length times width) is multiplied by 2. So, an increase in height would have a bigger impact on costs (because it is multiplied 4 times rather than 2).
  5. $d$ represents the number of days that have passed, so as summer progresses, this variable should increase. 
  6. Because each day that passes subtracts 64 from 3670, $L$ should go down as the summer passes (and $d$ increases).
  7. In this equation, there's a starting point, that goes down a little each day. Because the question is about reading, 3670 must be the starting number of pages that need to be read.
  8. And, each day the number 3670 decreases a little, in fact, it decreases by 64 pages a day.  64 represents the number of pages Garret reads each day.
  9. 5 is multiplied by $h$ which represents hours.  So, the boat must cost 5 dollars per hour.
  10. 8 is not multiplied by anything.  It is a constant.  It must cost 8 dollars to rent a boat, no matter how long it is rented for or how many riders are going in the boat. 
  11. Because the boats cost more per hour than they do per rider, it would be cheaper for the larger group (8 people) to rent for a shorter time than a larger group to rent for a shorter time. 
  12. In this case, you need to plug values into the equation and test it out:

$C=8+5(4)+3(8)=52$ (one boat, all eight people)

$C=8+5(4)+3(4)=40$ (one boat, only 4 people, so two boats with 4 people each would be \$80, which would be more).

Definitely cheaper for everyone to get in the same boat!