Question

Proszę zrobić zadania 4 , 5 b i c i 6 te co zą w zalaczniku

Answer 1

z.4

I.   - 8 ( 5 - 2x) = 3(x - 1/3)

-40 + 16 x = 3x - 1

16x - 3x = - 1 + 40

13x = 39 / : 13

x = 3

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II.  3(5 - x/3) = 2(1/3 -  x/2 ) + 2  1/3

15 - x = 2/3 - x + 2  1/3  / + x

15 =  3    - sprzeczność  - równanie nie ma rozwiązania

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z.5

b) 2x - (8 - x) = - 2( x - 5)

    2x - 8 + x = - 2x + 10

3x + 2 x = 10 + 8

5x = 18  / : 5

x = 18/5 = 3,6

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c)

(2/3) x -  4  2/3 = 2( x - 3)

(2/3) x - 4  2/3 = 2 x - 6

6 - 4  2/3 = 2 x - (2/3)x

1  1/3 = ( 1  1/3) x

x = 1

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 z.6

a)   1 - (3x - 88)/7 = 5x     / * 7

7 - (3x - 88) = 35 x

7 - 3x + 88 = 35 x

95 = 38 x

x = 95/38 = 5/2 = 2,5

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b)

- x/2 = 3 x - ( 3 +2 x)/4    / * 4

- 2x = 12 x - ( 3 + 2x)

-2 x = 12 x - 3 - 2 x

- 2 x = 10 x - 3

-2 x - 10 x = - 3

- 12 x = - 3  / : ( -12)

x = 3/12 = 1/4

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c)

3 - (3x)/2 = 5/8 - (4x - 3)/6      / * 24

72 - 36 x = 15 - 4*(4x - 3)

72 - 36 x = 15 - 16x + 12

72 - 27 = 36x - 16 x

45 = 20 x

x = 45/20 = 2,25

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d)

( 3 - 2x)/5 + 8 = (5x + 2)/2  - x       / * 10

6 - 4x + 80 = 25x + 10 - 10 x

86 - 10 = 15x + 4x

76 = 19 x

x = 76 : 19 = 4

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e)

(2x - 11)/4 + (19 - 2x)/2 =2 x    / * 4

2x - 11 + 38 - 4x = 8 x

27 - 2x = 8 x

27 = 8 x + 2 x

10x = 27

x = 27 : 10 = 2,7

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f)

1 - [ (x-3)/4 + 2/3] = x   / * 12

12 - [ 3*(x -3) + 2*4 ] = 12 x

12 - [ 3 x - 9 + 8 ] = 12 x

12 - [ 3x - 1 ] = 12 x

12 - 3x + 1 = 12 x

13 - 3 x = 12 x

13 = 12 x + 3 x

15 x = 13

x = 13/15

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