Futile argument regarding solution of 5=9 -2x

lookagain

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[math]5=9-2x\\ 5 + \blue{-9}=9-\blue{9} -2x \quad \text{subtract 9 on both sides}\\ [/math]

BigBeachBananas, you did not show 9 being subtracted from both sides.
You showed -9 being added to the left- hand side, while you showed 9
being subtracted from the right-hand side.

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\(\displaystyle 5 = 9 - 2x\)

\(\displaystyle 5 - 9 = 9 - 9 - 2x \ \ \ \ \ \ \ \ \ \) Subtract 9 from each side.

\(\displaystyle -4 = -2x\)
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BigBeachBananas, you did not show 9 being subtracted from both sides.
You showed -9 being added to the left- hand side, while you showed 9
being subtracted from the right-hand side.

______________________________________________________________________

\(\displaystyle 5 = 9 - 2x\)

\(\displaystyle 5 - 9 = 9 - 9 - 2x \ \ \ \ \ \ \ \ \ \) Subtract 9 from each side.

\(\displaystyle -4 = -2x\)
.
.
.
If you want to get technical, subtraction is defined as on [imath]\R[/imath] as [imath]\forall a,b\in\R:a,b:=a-b:=a+(-b)\in\R[/imath], where [imath]-b[/imath] is the inverse of [imath]b \in\R[/imath].
Furthermore, from Real Numbers under Addition form Group: [imath]∀?,?∈ℝ:?+(−?)∈ℝ[/imath]. In other words, subtraction is adding the inverse and it's a closed binary operation in the set of real numbers.
 
If you want to get technical, subtraction is defined as on [imath]\R[/imath] as [imath]\forall a,b\in\R:a,b:=a-b:=a+(-b)\in\R[/imath], where [imath]-b[/imath] is the inverse of [imath]b \in\R[/imath].

Then you need to be consistent with what you show on each side, as in my post # 10,
or as shown below, for example:

\(\displaystyle 5 = 9 - 2x\)

\(\displaystyle 5 + (-9) = 9 + (-9) - 2x \)

\(\displaystyle -4 = -2x \)
 
Then you need to be consistent with what you show on each side, as in my post # 10,
or as shown below, for example:

\(\displaystyle 5 = 9 - 2x\)

\(\displaystyle 5 + (-9) = 9 + (-9) - 2x \)

\(\displaystyle -4 = -2x \)
I don't know what you mean by "need to be consistent"? As stated above, I'm consistent with the principle and definition of subtraction. Whether I say five minus 9 or 5 add the inverse of 9, it does not make a difference in principle. If you're suggesting that I should be consistent with my presentation, then beat it. Math is expressions and relations.
[math]2 = 1+1 = \frac{4}{2} =2*1= 2! = 2\int_{0}^{\infty}\frac{x^{k-1}\cdot e^{-x/\theta}}{\Gamma(k)\theta^k}\,dx=two=dos...[/math]Am I supposed to pick one presentation of 2 and stick with it whenever I want to express 2?
If taht is wagt yuo're sgugeststnig tehn wyh are yuo albe to udenrsantd waht I am wirtnitg? Eevn Egnsilh deons't oeby taht law. Plseae sapre me teh ciritsicm wehn it mkaes no deffirefnce in prciinlpe.
 
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If you're suggesting that I should be consistent with my presentation, then beat it.

Of course you are showing it wrong, because you are presenting it wrong!
You are not showing it done the same way from one side to the other. You can
fix it or you can be the one to beat it. I will be checking your posts about it. Your
inconsistency in presentation is a hindrance for the student. Stop doing it.

[math]2 = 1+1 = \frac{4}{2} =2*1= 2! = 2\int_{0}^{\infty}\frac{x^{k-1}\cdot e^{-x/\theta}}{\Gamma(k)\theta^{k}\,dx=two=dos...[/math]

You are just changing the subject, going off on tangents, and being
argumentative. I tried to give you the benefit of the doubt, after I showed
the comparisons of posts # 10 and # 16, but your replies ended that.
 
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Of course you are showing it wrong, because you are presenting it wrong!
You're saying [imath]5+(-9) \neq 5 -9[/imath]. Say no more.
You can
fix it or you can be the one to beat it. I will be checking your posts about it.
Ok? Is this supposed to be a thread?
Your inconsistency in presentation is a hindrance for the student. Stop doing it.
The only hindrance here is you demand people do things your way. It's an open forum, and if you don't like my posts, then mute them as I will do so with yours after this post.
You are just changing the subject, going off on tangents
I don't think you got the point. There isn't just one way to express things in math.
being argumentative
What gave that away? I AM being argumentative. It's called making an ARGUMENT.
I tried to give you the benefit of the doubt, after I showed
the comparisons of posts # 10 and # 16, but your replies ended that.
Ok, more empty threads?
 
1) No, I am not stating that. The left-hand side is for "five plus negative nine." The
The right- hand side is for "five subtract nine." So, when you stated a description on
on the side about subtracting 9 on both sides, you were/are wrong, despite your
attempt to weasel out of it claiming "to get technical."

2) It does matter whether you like make a play on words with thread and another word.

3) Incorrect. Your attitude/tone shows up in the choices you make for your steps.
What you have chosen is to be haphazard going from one to the other, not being
careful to show from what you do on one side looks and acts the same way on the
other in a consistent way.

4) Of course there are more ways to express things in math, but there are proper times
(follow-up steps for a certain side of an equation, for example), and you have missed
that point.

5) Wrong. Being "argumentative" does not mean you are making an "argument."
The former means you have been displayed a lack of sufficient reasoning, of
which I am trying to clear things up. And you have also shown to be
argumentative in this thread by making statements based on emotionalism.

6) Please see 2) above.

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I need to see your future posts so I can give feedback about them to the forum
community. I would not "mute" them.
 
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