What is the process of switching signs in an equation called?

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Discussion Overview

The discussion revolves around the terminology and concepts related to switching signs in equations, particularly focusing on additive and multiplicative inverses. Participants explore the implications of these operations in both arithmetic and algebraic contexts.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants propose that switching signs in an equation relates to additive and multiplicative inverses, suggesting that if \( x + y = z \), then the additive inverse would lead to \( -z \).
  • Others argue that inverting an equation involves more than just switching signs, emphasizing that operations like addition and multiplication have specific inverses (subtraction and division, respectively).
  • A participant questions the terminology used, asking what it means to switch operations like addition to multiplication and vice versa.
  • Another participant clarifies that subtraction is defined as adding the additive inverse, and discusses how calculators interpret these operations.
  • Some participants express confusion over the terminology and the distinction between inverting equations and inverting operations.

Areas of Agreement / Disagreement

There is no consensus on the terminology used for switching signs in equations. Participants have differing views on the definitions and implications of additive and multiplicative inverses, as well as the concept of inverting operations versus equations.

Contextual Notes

Participants express uncertainty regarding the definitions and applications of terms like "invert" and "inverse," leading to varied interpretations of the original question. There are also unresolved mathematical steps and assumptions about the operations being discussed.

cowah22
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Hello,
I have a quick question for you guys.


What is it called when you switch the signs of the equation to their opposite?

For example, does 10 + 6 = 16 invert to 10 - 6 = 4 Is this additive inverse?


Or, does 14 x 7 = 98 invert to 14 / 7 = 2 Multiplicative inverse?

Thanks in advance.
 
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in short yes

if x*y=1 x is the multiplicatie inverse of y (also y is the multiplicatie inverse of x)
if x+y=0 x is the additive inverse of y (also y is the additive inverse of x)

Those are the nice names
bad people disrespect these numbers by calling them insults like opposite and reciprical
 
cowah22 said:
Hello,
I have a quick question for you guys.


What is it called when you switch the signs of the equation to their opposite?

For example, does 10 + 6 = 16 invert to 10 - 6 = 4


Or, does 14 x 7 = 98 invert to 14 / 7 = 2

wow
no
10 + 6 = 16
becomes
-10 +(-6) = -16

14 x 7 = 98
becomes
(1/14)*(1/7)=1/98

but what you likely want is
10 + 6 = 16
so
10=16-6 or 6=16-19
and
14 x 7 = 98
so
7=98/14 or 14=98/7

This is often used with variables like
10+x=16
so
x=16-10
x=6

14 y = 98
so
y=98/14
y=7
 
lurflurf said:
wow
no
10 + 6 = 16
becomes
-10 +(-6) = -16

14 x 7 = 98
becomes
(1/14)*(1/7)=1/98


So, when you invert a regular equation. x + y = z the answer will always be -z

But when you invert a multiplication/division equation x * y = z the answer will always the the reciprical of z.


What is it called when you switch - to / and + to * ?
 
Oh, silly me, I thought this was about inverse functions. I should pay more attention.
 
cowah22 said:
So, when you invert a regular equation. x + y = z the answer will always be -z

But when you invert a multiplication/division equation x * y = z the answer will always the the reciprical of z.


What is it called when you switch - to / and + to * ?
Perhaps it would help if you explained what in the world you are talking about! You started talking about "inverting" equations, now you are talking about inverting operations.

Yes, the "inverse" or "opposite" of addition is subtraction and the "inverse" of multiplication is division. Those apply only to specific operations, not to entire equations. I have no idea what you mean by "invert a regular equation".

If I wanted to solve x+ y= z for x, then I do the "inverse" of "add y" (since in the equation y is added to x) which is "subtract y". Subtracting y from both sides (whatever you do to one side of an equation you must do to the other) and get x+ y- y= z- y or x= z- y.
 
HallsofIvy, I'm curious more about inverting operations, and why:

+1 - +1 = 0 and -1 + -1 = -2 on my calculators.
 
Well good- then your calculator is working properly! "Subtraction" is technically defined as "adding the additive inverse". To your calculator (1)- (1) means 1+ (-1) which is, by definition of "additive inverse", 0. -1+ (-1) means you are adding two additive inverses, Since (1)+ (1)= 0, and addition satisfies both the "associative" and "commutative" laws,
(1+ 1)+ ((-1)+ (-1))= (1+ (-1))+ (1+ (-1))= 0+ 0= 0. That means that ((-1)+ (-1)) is the additive inverse of 1+ 1= 2. That is, (-1)+ (-1)= -2.
 
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