Question

If x+y=15 and x-y=-19 then what does xy=?

Answer 1

xy=34

Explanation:

Use elimination:

x+y=15

x-y+-19

2x=-4

x=-2

Plug -2 into x

-2+y=15

y=17

17 multiplied by -2 is 34

I dont know if you mean (x, y) or not but the answer to that would be (-2, 17).