Question

Sa se determine numerele reale care verifica expresiile:
|a|=8
|x|=-8
|-y|=2
|a+3|=1
|-x-4|=5
|3-6y|=12
|(x-2)(4-y)|=0

Answer 1

|a|=8
a=8
a=-8
a apartine {-8,8}
|x|=-8
x nu apartine lui R 
|-y|=2
-y=2
-y=-2
y=-2
-y=-2
y=-2
y=2
x partine {-2,2}
|a+3|=1
a+3=1
a+3=-1
a=1-3
a+3=-1
a=-2
1+3=-1
a=-2
a+3=-1
a=-2
a=-1-3 
a=-2
a=-4
a apartine {-2,-4}
|-x-4|=5
-x-4=5
-x-4=-5
-x=5+4
-x-4=-5
-x=5+4
-x-4=-5
x=-9
-x-4=-5
x=-9
-x=-5+4
x=-9
-x=-1
x=-9
x=1
x apartine lui {-9,1}
|3-6y|=12
3-6y=12
3-6y=-12
-6y=12-3
3-6y=-12
-6y=9
3-6y=-12
y=9:(-6)
3-6y=-12
y=9/-6
3-6y=-12
inmultim cu -1 fractia si ne da - 9/6
3-6y=-12
y=- 3/2
-6y=-12-3
y=3/2
y=-15:-6
y=- 3/2
y=-15/-6
y=- 3/2
y=15/6
y=- 3/2 y=5/2
y apartine {- 3/2, 5/2}