Răspuns :
răspuns :
|x|=5 => x=5;-5
|y|=7=> y=7;-7
1. x=5;y=7
5+7= 12
5-7=-2
2. x=-5;y=-7
-5+(-7)= -2
-5-(-7)= -5+7
=+2
sper ca te am ajutat
|x|=5 => x ∈ {-5, 5}
|y|=7 => y ∈ {-7, 7}
I. x+y= -5-7 = - 12
II. x+y= -5+7=2
III.x+y=5-7=-2
IV. x+y=5+7=12
I.x-y= -5-(-7)=-5+7=2
II. x-y=-5-(+7)=-5-7=-12
III.x-y=5-(-7)=5+7=12
IV. x-y=5-7=-2
Baftă...