Question

Calculati |x|+|y|,stiind ca |x+y+2|+|x-y|=0
REPEDE VA ROG!!!!!

Answer 1

x+y+2+x-y=0
⇒se reduce y cu y;
⇒x+2+x=0
⇒2x+2=0
⇒2x=0-2
⇒2x=-2
⇒x=[-2]/2
⇒x=-1;⇒x≠y⇔y=0;
⇒x+y=[-1]+0=-1;

Answer 2

I x+y +2 I + I x-yI = 0

⇒ x+y +2 = 0 ⇒ x+y = -2
   si
   x-y = 0

x+y = -2
x -y = 0
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2x +0 = -2
2x = -2 ⇒ x= -1

x-y = 0 ⇒ -1 -y = 0 ⇒ y = -1

IxI + IyI = I-1I +I-1I = 1 +1 = 2