Determine which of these relations are symmetric. the variables x, y represent integers. da. (x, y) e r if and only if x â y is positive. ob. (x, y) = r if and only if xy is negative. oc. (x, y) e r if and only if x + y is even. od. (x, y) r if and only if x = lyl. de. (x, y) e r if and only if x +y is positive.

step-by-step explanation:

descending order means to order the polynomials from the term with the largest exponent to the term with the smallest exponent.  

therefore, the correct answer is d.  

a

step-by-step explanation:

“ a line segment that has the endpoints on the circle and passes through the midpoint is called the diameter. the diameter is twice the size of the radius. a line segment that has its endpoints on the circular border but does not pass through the midpoint is called a chord. a circle is the same as 360 small circle up the number 0 . i hope this .