# Logic

##### Full Member
HEY Ryan, if 3 + 2 = 5, then 2 + 3 = ? Hi , is that relevant to my question tho?

5

#### Denis

##### Senior Member
Thing is, we never know what YOUR questions are!

• • topsquark and MarkFL

##### Full Member
Hi guys, may please anyone in its explanation explain to me what does "the same" means in math?
I mean, once we have two things are equal, x=y for example, then we say that x is the same as y or vice versa, what's confusing me what do we intend once we said "the same" ? I know it's simple logic but if my simple logic sucks, then I can't complete learning, and by you guys I believe that I will close those gaps.

I define the same is: two things the same regardless to its cosmetics, I mean regardless to what we call the variables, if they are referring to the same object then they are the "same" .. is this a good enough explanation to define what same is?

#### HallsofIvy

##### Elite Member
"x= y" means that "x" and "y" are two symbols both representing the same number ("same" here having its usual English meaning). Some times you will see "same" used to mean that two things are "equivalent" under a previously define equivalence relation.

• ##### Full Member
Hi guys! once again I'm sorry for posting like those question, but I really not succeeding solving those gaps by myself and thanks alot.

My problem is like this, lets assume that's x=y=z , then we conclude x=z ! it's really fine but it's a conclusion and not given data.
so now if I do z+m= 5, can I assign instead of z, x? I mean to write x+m=5 ?! what's confusing me because we conclude that x=z but it's not given information, given x=y=z, and from this we conclude x=z so I'm asking can I depend also on my implicitly conclusion of the given data(x=y=z) ?! thanks alot !

##### Full Member
Hi guys, I'm really struggling something which I couldn't find a solution for it!
I always going to negatively what result I get.
I mean, lets assume I get from equation logic that x=2y.
so " I " can assume x != 2y (not equal) .. why not? while the logic is giving me opportunity to do whatever things in general why not claiming that assumption?! I can think in general and one of possibilities of general is x != 2y .. so it's possible !

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#### JeffM

##### Elite Member
Yes, you may make up any mathematics you want.

$$\displaystyle 6 = 2 * 3 \implies 6 \ne 2 * 3.$$

#### tkhunny

##### Moderator
Staff member
3 = 5 - False
4 = 4 - True
x = 2y - Conditionally True. One must pick x and y that work.

• topsquark

#### Otis

##### Senior Member
… I always going to negatively what result I get …
I don't understand what you mean.

Please post the complete exercise statement. • topsquark