why am I subtracting on the first part and dividing on the second. why am I not dividing on both????

Just something I have accepted but hate that I dont really get it.

Thanks in advance hope everyone is having a great holiday!

- Thread starter spausm
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why am I subtracting on the first part and dividing on the second. why am I not dividing on both????

Just something I have accepted but hate that I dont really get it.

Thanks in advance hope everyone is having a great holiday!

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- Nov 12, 2017

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- 3,039

ItOk so I'm not sure if this is just so obvious or I just missed this part of the lesson.

why am I subtracting on the first part and dividing on the second. why am I not dividing on both????

View attachment 10751

Just something I have accepted but hate that I dont really get it.

Thanks in advance hope everyone is having a great holiday!

IF you divided in first part, what would you divide by?why am I subtracting on the first part and dividing on the second. why am I not dividing on both????

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3z + 9 + 14z = 4z + 5

The goal is to isolate symbol z. That is, we need to manipulate the equation, until we have the form:

z = some constant

Before we isolate z, we need to combine like-terms. (After all, we cannot isolate symbol z, as long as it appears on both sides, right?) Therefore, combining like-terms involves adding and subtracting terms*first*.

After we combine all of the variable terms (on one side) and all of the constant terms (on the other side), we have:

13z = -4

Now we're ready to obtain a single z all by itself (form: z=constant); division does that for us (the final step).

You'll be solving many linear equations like this; with more practice, these steps will all seem natural. :cool:

The goal is to isolate symbol z. That is, we need to manipulate the equation, until we have the form:

z = some constant

Before we isolate z, we need to combine like-terms. (After all, we cannot isolate symbol z, as long as it appears on both sides, right?) Therefore, combining like-terms involves adding and subtracting terms

After we combine all of the variable terms (on one side) and all of the constant terms (on the other side), we have:

13z = -4

Now we're ready to obtain a single z all by itself (form: z=constant); division does that for us (the final step).

You'll be solving many linear equations like this; with more practice, these steps will all seem natural. :cool:

Last edited:

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Note that 4 + 5 = 9 AND 9 - 4 = 5 And 9 - 5 = 4. Also 7 + 2 = 9 AND 9 - 2 = 7 AND 9 - 7 = 2.Ok so I'm not sure if this is just so obvious or I just missed this part of the lesson.

why am I subtracting on the first part and dividing on the second. why am I not dividing on both????

View attachment 10751

Just something I have accepted but hate that I dont really get it.

Thanks in advance hope everyone is having a great holiday!

Do you see a pattern???