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Re: avoid combining like terms in algebraic expression

  • To: mathgroup at smc.vnet.net
  • Subject: [mg121149] Re: avoid combining like terms in algebraic expression
  • From: David Bailey <dave at removedbailey.co.uk>
  • Date: Wed, 31 Aug 2011 06:05:56 -0400 (EDT)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com
  • References: <j3ieh3$sda$1@smc.vnet.net>

On 30/08/2011 11:37, Phil Hammond wrote:
> I'm generating problems for basic algebra students, and I would like
> to present expressions with like terms (e.g. 3x + 4x) and have the
> students combine them in their answers. Could somebody help me
> persuade Mathematica to refrain from combining them automatically?
>
> Thanks-
>
It is not completely clear what you mean by 'generating' - because of 
course, you can type anything you want into a notebook. However, perhaps 
the following is what you want:

HoldForm[3 x]+HoldForm[4 x]

3x + 4x

If the constants come from some other calculation then they would need 
injecting inside the HoldForm expressions:

c3=3;
c4=4;
With[{c3=c3,c4=c4},HoldForm[c3 x]+HoldForm[c4 x]]

Note that these expression contains HoldForm invisibly within them, so 
it would not be suitable to naively copy/paste into another Mathematica 
expression.

David Bailey
http://www.dbaileyconsultancy.co.uk





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