Evaluate the variable expression x y for the given values of x and y. (If an answer is undefined, enter UNDEFINED.) x = 0; y = 21

go on the tube you might find some information there

in the attachment.   i didn't see your choices.   the word which means there is choices.

step-by-step explanation:

(x,y)

x tells you how much left or right you go from the origin

y tells you how much down or up you go from the origin

so for example (-3,2), you go left 3 and up twice. i denoted which of the ordered pairs is which in my graph.