SOLUTION: How so you solve this problem? Photoworks.com charges $7.00 forr processing a 24-exsposure roll and $10.00 for processing a 36-expsosure. After Karens photography field trip, she

Question 27818: How so you solve this problem? Photoworks.com charges $7.00 forr processing a 24-exsposure roll and $10.00 for processing a 36-expsosure. After Karens photography field trip, she sent 19 rolls of film to photoworks and pid $151 dollars for processing. How many rolls of each type were processed
Answer by bmauger(101) (Show Source): You can put this solution on YOUR website!
This is a type of problem solved by 2 simultaneous linear equations. You can tell this because you are trying to solve for two unknowns (# of 36-rolls & # of 24-rolls) Let x = the number of 24-exposure rolls that Karen submits, and y equal the number of 36-rolls submitted. From the problem, we are told that the total number of rolls is 19. So the number of 24-rolls (x) and the number of 36-rolls (y) must add up to 19. Or:

But we can't yet solve this for x or y without knowing something more about them. The other part of the problem says she paid $151 for the total. The amount she'll pay for 24 exposure rolls (x) will be $7/roll or 7x. The amount she'll pay for 36-rolls is $10/roll or 10y. The total she'll pay is the sum of these two amounts, or:

Now we have to solve these equations. The easiest way is using substitution, so we'll rewrite the first equation for x:
subtract y from both sides:

Now we can substitute 19-y for x in the second equation:
Substitute:
Distibute:
Rearrange:
Divide:

So she'll process 6 36-exposure rolls, and 19-6= 13 rolls of 24 exposures.
Check.
RELATED QUESTIONS
cord camera charges $9.00 for processing a 24-exposure roll of film and $12.60 fo... (answered by stanbon)

PhotoLab charges $9.00 for processing a 24-exposure roll of film and $12.00 for... (answered by macston)

Can you please help me with this problem: A photo-processing kiosk charges $0.25 for (answered by josmiceli)

A well driller charges $9.00 per foot for the first 10 feet, $9.10 per foot for the next... (answered by ikleyn)

A theatre box office charges a $8 processing fee for a customer order and $12 for each... (answered by ankor@dixie-net.com)

I need help setting up this problem so I can solve it. Can anyone please help? A... (answered by checkley75,rmromero)

1.Tiny Tot Day Care Center has changed it's rates. IT now charges $350 a week for... (answered by stanbon)

Train Speed: A train leaves Los Angeles at 2:00 PM. A second train leaves the same... (answered by josmiceli)