determine o conjunto solução das equações modulares.
a) |4×-2|=|2×-4|
b) |3×+5|=|×-5|
c) |7×-4|=|7×-10|
Soluções para a tarefa
Respondido por
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a) |4×-2|=|2×-4|
Se
4x - 2 > 0 e 2x - 4 >0 ==> 4x - 2 = 2x - 4
2x = -2
x = -1
______________________________________________________________
Se
4x - 2 < 0 e 2x - 4 < 0 ==> -4x + 2 = - 2x + 4
(-1) -6x = 2
6x = -2
x = -2/6
x = -1/3
__________________________________________
Se
4x - 2 > 0 e 2x - 4 < 0 ==> 4x - 2 = -2x + 4
6x = 6
x = 6/6
x = 1
____________________________________________
Se
4x - 2 < 0 e 2x - 4 > 0 ==> -4x + 2 = 2x - 4
(-1) -6x = -6
6x = 6
x = 1
S = { -1,-1/3, 1}
_______________________________________________________
b) |3×+5|=|×-5|
Se
3×+5> 0 e x - 5 >0 ==> 3x + 5 = x - 5
2x = 0
x = 0/2
x = 0
_____________________________________________________________
Se
3×+5< 0 e x - 5 < 0 ==> -3x -5 = -x + 5
-4x = 5 + 5
(-1) -4x = 10
4x = -10
x = -10/4
x = -5/2
__________________________________________________________
Se
3×+5> 0 e x - 5 <0 ==> 3x + 5 = -x + 5
3x + x = 5 -5
4x = 0
x = 0/4
x = 0
___________________________________________________________
Se
3×+5< 0 e x - 5 >0 ==> -3x -5 = x - 5
(-1) -4x = 0
4x = 0
x = 0/4
x = 0
S = {0, -5/2}
__________________________________________________________
c) |7×-4|=|7×-10|
7×-4 >0 e 7×-10> 0 ==> 7x - 4 = 7x - 10
0x = -6
x = 6/0 = oo
_________________________________________________________
|7×-4| <0 e |7×-10| < 0 ==> -7x + 4 = -7x + 10
0x = 6
x = 6/0 = oo
___________________________________________________________
|7×-4| >0 e |7×-10| < 0 == > 7x - 4 = -7x + 10
14x = 14
x = 14/14
x = 1
__________________________________________________________
|7×-4| <0 e |7×-10| >0 ==> -7x + 4 = 7x - 10
-14 x = -10 -4
(-1) -14x = -14
14x = 14
x = 14/14
x = 1
S = { oo, 1} obs: oo = indeterminação!
Se
4x - 2 > 0 e 2x - 4 >0 ==> 4x - 2 = 2x - 4
2x = -2
x = -1
______________________________________________________________
Se
4x - 2 < 0 e 2x - 4 < 0 ==> -4x + 2 = - 2x + 4
(-1) -6x = 2
6x = -2
x = -2/6
x = -1/3
__________________________________________
Se
4x - 2 > 0 e 2x - 4 < 0 ==> 4x - 2 = -2x + 4
6x = 6
x = 6/6
x = 1
____________________________________________
Se
4x - 2 < 0 e 2x - 4 > 0 ==> -4x + 2 = 2x - 4
(-1) -6x = -6
6x = 6
x = 1
S = { -1,-1/3, 1}
_______________________________________________________
b) |3×+5|=|×-5|
Se
3×+5> 0 e x - 5 >0 ==> 3x + 5 = x - 5
2x = 0
x = 0/2
x = 0
_____________________________________________________________
Se
3×+5< 0 e x - 5 < 0 ==> -3x -5 = -x + 5
-4x = 5 + 5
(-1) -4x = 10
4x = -10
x = -10/4
x = -5/2
__________________________________________________________
Se
3×+5> 0 e x - 5 <0 ==> 3x + 5 = -x + 5
3x + x = 5 -5
4x = 0
x = 0/4
x = 0
___________________________________________________________
Se
3×+5< 0 e x - 5 >0 ==> -3x -5 = x - 5
(-1) -4x = 0
4x = 0
x = 0/4
x = 0
S = {0, -5/2}
__________________________________________________________
c) |7×-4|=|7×-10|
7×-4 >0 e 7×-10> 0 ==> 7x - 4 = 7x - 10
0x = -6
x = 6/0 = oo
_________________________________________________________
|7×-4| <0 e |7×-10| < 0 ==> -7x + 4 = -7x + 10
0x = 6
x = 6/0 = oo
___________________________________________________________
|7×-4| >0 e |7×-10| < 0 == > 7x - 4 = -7x + 10
14x = 14
x = 14/14
x = 1
__________________________________________________________
|7×-4| <0 e |7×-10| >0 ==> -7x + 4 = 7x - 10
-14 x = -10 -4
(-1) -14x = -14
14x = 14
x = 14/14
x = 1
S = { oo, 1} obs: oo = indeterminação!
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