Question

Doar exercitiul 10 daca ma puteti ajuta va rog :)

Answer 1

Răspuns:

Explicație pas cu pas:

10.

a) 8 x + 1 = 5 x - 5

   8 x - 5 x = - 5 - 1

   3 x = - 6

      x = ( - 6 ) : 3

      x = - 2 ∈  Z

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b)

- 4 x + 10 = 10 - 2 x

- 4 x + 2 x = 10 - 10

- 2 x = 0

x = 0 ∈ Z

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c)

- 3 x + 5 = - 9 x + 4 x

- 3 x + 5 x = - 5

2 x = 5

x = 5/2 ∉ Z ( ecuatia nu are ca solutie unh nr. intreg )

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d)

2 ( x + 1 ) = 6

x + 1 = 6 : 2

x = 3 - 1

x = 2 ∈ Z

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e)

5( x - 1 ) = 2 x + 7

5 x - 5 = 2 x + 7

5 x - 2 x = 7 + 5

3 x = 12

x = 12 : 3

x = 4 ∈ Z

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f)

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

3 x + 6 = 2 x + 8

3 x - 2 x = 8 - 6

x = 2 ∈ Z

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g)

6 = 4( x + 1 ) - 2 ( x + 2 )

6 = 4 x + 4 - 2 x - 4

6 = 2 x

x = 6 : 2

x = 3 ∈ Z

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h)

4 = 5( x + 1 ) - 6

4 = 5 x + 5 - 6

4 = 5 x - 1

5 x = 4 + 1

x = 5 : 5

x = 1 ∈ Z

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i)

3( 2 x - 5 ) = 6( x - 1 ) - 9

6 x - 15 = 6 x - 6 - 9

6 x - 6 x = - 15 + 15

0 = 0,  ∀ x ∈ Z