Question

if x+y=15 and x-y=19 then what is the product of x and y

Answer 1

have you started to answer or are you completly stuck?

Answer 2

stuck i know y must be negative

Answer 3

add two equations:
2x = 34
x = 17
so y= -2

and xy = -34

Answer 4

you shouldnt give the answer like that give him the 1st step and let him try to figure out the rest