Posted by olivia on Tuesday, December 20, 2011 at 6:45pm.
prove xy=yx, for all integers

math  MathMate, Wednesday, December 21, 2011 at 9:28am
I do not know what grade you're in, but questions of this sort could go quite deep into algebra.
Since x,y are integers, which belong to a ring in which additions are commutative, so if we write the subtractions as inverses of addition, the above would be invoking commutativity in the ringaddition:
xy
=(x)+(y) inverse of addition
=(y)+(x) commutativity of addition
=yx inverse of addition
For highschool algebra, then it would be the commutative property of addition and subtraction.
Answer This Question
Related Questions
 discrete math  Let A= {for all m that's an element of the integers  m=3k+7 for...
 math  Let f:ℤ+ → ℤ+ be the function defined by: for each x &#...
 math help please  Let f:ℤ+ → ℤ+ be the function defined by: ...
 discrete math  Let f:ℤ+ → ℤ+ be the function defined by: for...
 Math!!! Please help!!!  Find the coefficient of x^7 for (x3)^11 Use the ...
 math  . Prove that x  y = y – x; for all integers x and y.
 Mathematics  Find the coefficient of x^7 for (x3)^11 Use the binomial theorem ...
 Math, Please Help  1) Given the arithmetic sequence an = 4  3(n  1), what is ...
 Math  1) Given the arithmetic sequence an = 4  3(n  1), what is the domain ...
 discrete math  use a direct proof to show that the product of two odd numbers ...
More Related Questions