

Line 30: 
Line 30: 

<math>a=a</math> 

<math>a=a</math> 




− 
This plainly shows that any number is equal to its negative. 
+ 
This plainly shows that any number is equal to its [[Negative Numbersnegative]]. 





[[Category:Mathematics]] 

[[Category:Mathematics]] 
Revision as of 19:35, February 26, 2009
Any number is equal to its negative
left
Assume a and b are real numbers.
We start with:
From this we can also conclude:
Square each side:
A negative times a negative is a positive:
Take the square root:
We get:
From our original equation b=a:
This plainly shows that any number is equal to its negative.