This is a question about mathematical terminology learned in school in different parts of the world.
I'm from North America (born and raised in Canada, now living and working in the United States).
For me, if we rearrange an equation to put one variable by itself on one side, such as
Ax + B = C
becoming
x = (CB)/A
I would call that "solving for x" or "isolating x".
I seem to recall encountering other words for this process, perhaps even on these very boards. But I'm drawing a blank at the moment. Can anybody help me remember other words for this? (For instance, do people in the UK sometimes call this by a different name? Or India, South Africa, etc., etc.?)
synonyms for "solve for x" or "isolate x"
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Re: synonyms for "solve for x" or "isolate x"
In spanish we use the ones you said, and sometimes "encontrar x" (find x). Is that the synonym you were looking for?
 dudiobugtron
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Re: synonyms for "solve for x" or "isolate x"
We often call this "making x the subject". I'm interested to hear some other names for it too though!
Re: synonyms for "solve for x" or "isolate x"
Aha! I just remembered it!
It was "make x the subject".
I don't remember hearing that when I was a student. But nevertheless, maybe it is used in North America, but only by some people.
Or perhaps it's not North American at all.
Anyone happen to know?
(Heh. Ninja'd!)
It was "make x the subject".
I don't remember hearing that when I was a student. But nevertheless, maybe it is used in North America, but only by some people.
Or perhaps it's not North American at all.
Anyone happen to know?
(Heh. Ninja'd!)
 TheGrammarBolshevik
 Posts: 4878
 Joined: Mon Jun 30, 2008 2:12 am UTC
 Location: Going to and fro in the earth, and walking up and down in it.
Re: synonyms for "solve for x" or "isolate x"
How about "determine X"? For example, someone asked for help with the following problem on reddit recently: "Assume f: Z to A given by f(x)=2x5 is onto. Determine the set A."
Nothing rhymes with orange,
Not even sporange.
Not even sporange.
Re: synonyms for "solve for x" or "isolate x"
(UK here)
I usually here "find x" or "solve for x" (or just "solve" it's obvious what variable to solve for) with "make x the subject" being used only in slightly more formal contexts.
I usually here "find x" or "solve for x" (or just "solve" it's obvious what variable to solve for) with "make x the subject" being used only in slightly more formal contexts.
my pronouns are they
Magnanimous wrote:(fuck the macrons)
Re: synonyms for "solve for x" or "isolate x"
dudiobugtron wrote:We often call this "making x the subject". I'm interested to hear some other names for it too though!
I'm in the U.S. (Texas) and have not heard that one before. Usually it's just "solve for x."
 dudiobugtron
 Posts: 1098
 Joined: Mon Jul 30, 2012 9:14 am UTC
 Location: The Outlier
Re: synonyms for "solve for x" or "isolate x"
They do mean slightly different things for me in New Zealand. "Make x the subject" means to rearrange the equation so that x is isolated; nominally you don't need to find an 'answer'. 'Making x the subject' is really the technique you need to use in order to solve for x.
egs:
You wouldn't ask someone to "make x the subject" of, say, 2x+4=8. You would ask them to 'solve for x' or 'calculate x', since you can get a numerical answer.
You'd normally use "make x the subject" for an equation like y=2x+4, or y=mx+c. (I guess you could also write "solve for x, in terms of m, y and c"...)
egs:
You wouldn't ask someone to "make x the subject" of, say, 2x+4=8. You would ask them to 'solve for x' or 'calculate x', since you can get a numerical answer.
You'd normally use "make x the subject" for an equation like y=2x+4, or y=mx+c. (I guess you could also write "solve for x, in terms of m, y and c"...)
Re: synonyms for "solve for x" or "isolate x"
dudiobugtron wrote:You'd normally use "make x the subject" for an equation like y=2x+4, or y=mx+c. (I guess you could also write "solve for x, in terms of m, y and c"...)
Another option there is "express x in terms of m, y and c".

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Re: synonyms for "solve for x" or "isolate x"
Here in New England I usually hear "Solve for x" or "Find x". I have never heard "isolate x", "determine x", or "make x the subject" before.
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