# Tutor.com Linear Equations Session

##### Feb. 12, 2014

Session Transcript - Math - Algebra, 2/4/2014 8:57PM - Tutor.comSession Date: 2/4/2014 8:57PM
Length: 26.2 minute(s)
Subject: Math - Algebra

System Message
[00:00:00] *** Please note: All sessions are recorded for quality control. ***

Guest (Customer)
[00:00:00] 4.Photos The cost of having photos taken includes sitting fee and \$12 for each portrait.The cost of 3,6,and 9 photos respectively is \$51,\$87 and \$123.What is the sitting fee

Liz N (Tutor)
[00:00:17] Hi! Let's get started.

Guest (Customer)
[00:00:26] hello

Liz N (Tutor)
[00:00:28] I see you posted a problem above. Have you started working on it yet?

Guest (Customer)
[00:00:28] alright
[00:00:47] so there is a sitting fee and each protrait is \$12

Liz N (Tutor)
[00:01:04] Yep, very good. :)
[00:01:21] Any ideas of how to figure out the sitting fee?

Guest (Customer)
[00:01:52] yes normally it would be 12x3=36
[00:02:05] but here it says 3 protraits is \$51
[00:02:20] so i would subtract 51-26=15

Liz N (Tutor)
[00:02:36] 51-36 = 15
[00:02:40] Right! :)

Guest (Customer)
[00:02:41] and 15 divided by 3 is 5 dollars sitting fee for each protrait

Liz N (Tutor)
[00:03:13] Well, kind of. A sitting fee is a fee that is charged each time you "sit" for a portrait.
[00:03:25] So you pay one flat fee regardless of how many pictures are taken.
[00:03:43] For example, I might pay \$15 for the sitting fee and then get 3 pictures taken.
[00:03:59] OR I might pay \$15 for the sitting fee and get 17 pictures taken! :)

Guest (Customer)
[00:04:09] but a portrait is \$12

Liz N (Tutor)
[00:04:13] So the sitting fee is not a "per picture" fee.
[00:04:26] Right, the cost of each picture (portrait) is separate.

Guest (Customer)
[00:04:26] its just kind of an initial fee?

Liz N (Tutor)
[00:04:31] Exactly! :)

Guest (Customer)
[00:04:37] ok
[00:04:45] but there is this one problem i am stuck on

Liz N (Tutor)
[00:04:48] We could write an equation to show the situation.

Guest (Customer)
[00:04:48] i has a graph
[00:05:00] it has a graph

Liz N (Tutor)
[00:05:01] Yep, that makes a lot of sense for this kind of problem.

Guest (Customer)
[00:05:10] no i mean another problem

Liz N (Tutor)
[00:05:23] Oh - would you like to finish this problem first?

Guest (Customer)
[00:05:24] can you help me with another problem
[00:05:37] oh ya
[00:05:43] didnt i finish it though?
[00:05:51] \$5 sitting fee

Liz N (Tutor)
[00:06:17] And remember, you said it was a \$15 sitting fee, not \$5.
[00:06:32] Because it's an INITIAL cost, not dependent on how many pictures we take.
[00:06:37] Let's pick some variables.
[00:06:50] How about C for total Cost and S for sitting fee?

Guest (Customer)
[00:07:16] what no i meant\$15 dollars for the 3 pictures

Liz N (Tutor)
[00:07:20] and p for each portrait

Guest (Customer)
[00:07:32] and that divided by 3 would be 5 dollars

Liz N (Tutor)
[00:07:42] You're right - it is \$15 for three portraits, but we don't divide it.
[00:07:46] I'll show you... :)
[00:08:40] So that's what you already figured out.
[00:08:51] Now let's see what the sitting fee is for 6 photos...
[00:09:44] The sitting fee is still \$15! :)
[00:09:51] Let's check what it is for 9 photos...
[00:10:42] \$15 again! :)
[00:10:53] So do you see how the sitting fee is ALWAYS the same?
[00:11:00] It's is a base fee that never changes.

Guest (Customer)
[00:11:13] is that an S or a 5

Liz N (Tutor)
[00:11:23] Which is why we wouldn't say "It's \$5 per photo if you get 3 photos"
[00:11:29] It's an S for sitting fee.
[00:11:35] Sorry - that was a bad variable to pick!
[00:11:57] Does this make sense now?

Guest (Customer)
[00:12:05] yes

Liz N (Tutor)
[00:12:09] Great!

Guest (Customer)
[00:12:09] thank you

Liz N (Tutor)
[00:12:17] Okay, let's do that other problem you were asking about. :)

Guest (Customer)
[00:12:27] alright
[00:13:29] 1.Determine wether each table represents a linear or a nonlinear function.Explain
[00:13:35] and there is a table
[00:13:42] can i erase the stuff you wrote
[00:13:46] never mind
[00:14:26] no its a table

Liz N (Tutor)
[00:14:48] Right, but an easy way to determine if it's linear or not is to graph the points.
[00:14:56] If they fall in a straight line, it's linear.
[00:15:01] If they don't, it's not linear.
[00:15:28] You can also check just the numbers if you want. Do they increase by the same amount between each set? Then it's linear.
[00:15:56] So your x's are all increasing by 1 each time.
[00:16:25] Your y's are increasing by one each time. It's consistent, so that means it's linear.
[00:17:15] If you graph it, it shows that it's linear.
[00:17:25] Does that make sense to you?

Guest (Customer)
[00:17:35] yes but give me a minute to write it down on my paper

Liz N (Tutor)
[00:18:04] Go ahead and type it here in the chatbox just so I can check to make sure you've got it. :)
[00:19:27] What did you come up with?
[00:20:23] I'll only be able to wait for a few more minutes. If I don't hear from you soon, I'll need to end this session so I can help other students. You can sign back in when you are ready to continue working.

Guest (Customer)
[00:20:31] sry
[00:20:38] i was doing something

Liz N (Tutor)

Guest (Customer)
[00:22:15] um is the
[00:22:32] x intercept on the horizontal or vertical side

Liz N (Tutor)
[00:22:52] You can extend the line to find out.
[00:23:04] But I don't think that information is important for this problem..
[00:24:58] Are you still there?

Guest (Customer)
[00:25:14] yes

Liz N (Tutor)
[00:25:32] Do you have any questions about anything we went over tonight?

Guest (Customer)
[00:25:51] no

Liz N (Tutor)
[00:25:54] Great!

Guest (Customer)
[00:25:54] thank you very much
[00:25:56] good bye

Liz N (Tutor)
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