Question

dê a raiz das equações

a) 2(x+3)=30
b)3(2x+4)=4(x+6)
c)2(x +7)-3(5-x)=8
d)10-(x+6)=20
e)3x= -45-2x
f)m-5= - 7
g)3y/4-6=12
h)2(n+3)-5n=6

Answer 1

a) 2(x+3)=30

   2x + 6 = 30

   2x = 30 - 6

     x = 24/2 = 12

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b)3(2x+4)=4(x+6)

   6x + 12 = 4x + 24

   6x - 4x = 24 - 12

          2x = 12

           x = 12/2 = 6

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c)2(x +7)-3(5-x)=8

  2x + 14 - 15 + 3x = 8

  5x = 8 - 14 + 15

  5x = 9

    x = 9/5

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d)10-(x+6)=20

   10 - x - 6 = 20

        - x = 20 - 10 + 6

        -x = 16   (-1)

        x = - 16

________________________

e)3x= -45-2x

 3x  + 2x = - 45

         5x = - 45

           x = -45/5

          x = - 9

_________________________

f)m-5= - 7

  m = - 7 + 5

  m = - 2

__________________________

g)3y/4-6=12

3y/4 = 12 + 6

3y/4 = 18

3y = 18* 4

3y = 72

  y = 72/3  

  y = 24

_____________________________

h)2(n+3)-5n=6

   2n + 6 - 5n = 6

   - 3n = 6 - 6

      -3 n = 0

          n = 0/3

          n = 0