Question

O numero - 2 e raiz de quais equacoes ?
a) x + 4 = 6 + 2x
b) 5 x + 1 = 4x
c) 2 ( x + 2 ) = 3 ( 4 + 2 x ) =
d) 5 x + 1 = 4x =

Answer 1

letra C pois 

2(x+2)=3(4+2)
2x+4=12+6x
2x-6x=12-4
-4x=8
4x= -8 (-1)
x= -8
     ---
      4

X= -2

Answer 2

a)
x + 4 = 6 + 2x
4 - 6 = 2x - x
- 2 = x
x = - 2   (sim)

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b)
5 x + 1 = 4x
5x - 4x = - 1
x = - 1

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c)
2.( x + 2 ) = 3.( 4 + 2 x ) 
2x + 4 = 12 + 6x
4 - 12 = 6x - 2x
- 8 = 4x
4x = - 8
x = -8/4
x = - 2  (sim)

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d)
5x + 1 = 4x
5x - 4x = - 1
x = - 1

Resp.: alternativas "a"  e "c".