Question

|x+y|= |x|+|y| if x and y are both positive? Both negative? What happens if x is negative and y is positive explain.?

Answer 1

solve it by cases

Answer 2

|x+y|= |x|+|y|
Case 1:
x>= 0 , y > = 0
x+ y > = 0

x + y = x + y, which is true for all x y,
so quadrant 1 is completely shaded