Tutor.com Real Numbers Session

Sep. 10, 2013

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Session Transcript - Math - Algebra II, 9/8/2013 10:23PM - Tutor.comSession Date: 9/8/2013 10:23PM
Length: 16.2 minute(s)
Subject: Math - Algebra II


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

Guest (Customer)
[00:00:00] 5x+4=3x-4

Miranda S (Tutor)
[00:00:09] Hello, welcome to tutor.com !

Guest (Customer)
[00:00:17] hello!

Miranda S (Tutor)
[00:00:34] So, you have an expression and you would like to solve for x, correct?

Guest (Customer)
[00:00:42] yes!

Miranda S (Tutor)
[00:00:49] Great! We can do that!
[00:01:17] Alright. Do you have ideas on where we can start?

Guest (Customer)
[00:01:29] no i dont.

Miranda S (Tutor)
[00:02:00] No problem! To solve for x, we want to isolate all the terms containing "x" on one side of the equation.
[00:02:33] So, let's say we want all of the x terms on the left. How can we move that 4 over to the right side?

Guest (Customer)
[00:03:14] minus 4 under the pos 4?

Miranda S (Tutor)
[00:03:21] Right!
[00:03:32] But, remember, we have to do this to both sides.
[00:04:06] Do you want to write what our equation looks like after we subtract 4 from both sides?
[00:05:16] Great job!

Guest (Customer)
[00:05:16] ?

Miranda S (Tutor)
[00:05:21] That's right!
[00:05:43] Ok, now we have 5x on the left, but we still have that 3x on the right, how can we move that over?

Guest (Customer)
[00:06:14] i dont know the end steps are more confusing?

Miranda S (Tutor)
[00:06:22] No problem
[00:06:46] Similarly to how we just subtracted 4 from both sides, we can also subtract 3x from both sides.
[00:06:59] This will isolate the x terms on one side of the equation, so we can combine them.
[00:07:29] Would you like to try writing it?
[00:07:50] Right! Good work!
[00:08:30] Ok, this is right, but don't forget that there is a negative sign on the 8
[00:08:45] So, x = ?

Guest (Customer)
[00:09:13] -4! and i have a question why did we subtract do you always subtract?

Miranda S (Tutor)
[00:09:18] Good!

Guest (Customer)
[00:09:24] why didnt we add 4 or 3x

Miranda S (Tutor)
[00:09:29] Not necessarily.
[00:09:54] We perform the operation that is opposite to the sign and operation of the term we are trying to eliminate, or move over.

Guest (Customer)
[00:10:17] how do you know which one to move over

Miranda S (Tutor)
[00:10:19] For example, if it had been 5x = -3x -8, we would have needed to add 3x
[00:10:49] Well, when I say "move over" I am typically referring to addition and subtraction...
[00:11:12] Let me think of an example.

Guest (Customer)
[00:11:15] okay thanks alot

Miranda S (Tutor)
[00:12:09] So, I would start with "moving over" the 1 from right to left, by adding 1 to both sides.
[00:12:43] If "move over" is confusing, you can think of it another way, its just kind of a habit of mine i suppose.
[00:13:07] Does this make sense so far?

Guest (Customer)
[00:13:58] yes it does so you always pick the number on the far right

Miranda S (Tutor)
[00:14:21] Not necessarily. I look for what is the simplest.

Guest (Customer)
[00:14:32] oh okay i see

Miranda S (Tutor)
[00:14:37] In this case, we have a small value, -1. So I chose that.
[00:14:52] You could also just have easily subtracted 3 from both sides.
[00:15:00] You would come up with the same answer.

Guest (Customer)
[00:15:18] oh okay i get it thinks a lot thats all i have

Miranda S (Tutor)
[00:15:28] Your welcome!
[00:15:41] Glad to help! Have a wonderful night!

Guest (Customer)
[00:16:07] you too goodbye!