Question

cine poate rezolva ex 5 urgent dau 55 de puncte VA ROG URGENTTT

Answer 1

5.
a)Numitor comun 48
21x=30x-18
-9x=-18 =>x=2
b)(3/2 - 15/4)(x-1)=27/4
-3/4(x-1)=27/4
x-1=27/4 • (-4/3)
x-1=-9 =>x=-8
c)5x-28x+12+17=54x-42-24x-15-20
-23x+27=30x-79
-53x=-106 =>x=106/53=2
d)Numitor comun 6
4x+18-20x-110+27=8-9x-24
-16x-65=-9x-16
-7x=49 =>x=-7

Answer 2

a)   7 x / 16 = 5 x / 8 - 9 / 24

7 x / 16 - 5 x / 8 = - 3 / 8

7 x / 16 - 10 x / 16 = - 6 / 16  l  : 16

7 x - 10 x = - 6

- 3 x = - 6    l  : - 3

x = 2

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b) 1 intreg si  1 / 2= ( 1 x 2 + 1 ) / 2 = 3 / 2

3 intregi si 3 / 4 = ( 3 x 4 + 3 ) / 4 = 15 / 4

( 3 / 2 - 15 / 4 ) ( x - 1 ) = 7 - 1 / 4

( 6 / 4 - 15 / 4 ) ( x - 1 ) = 28 / 4 - 1 / 4

( - 9 / 4 ) ( x - 1 ) = 27 / 4

x - 1 = 27 / 4  :   ( - 9 / 4 )

x - 1 = - 27 / 4  x 4 / 9

x - 1 = - 3

x = - 3 + 1

x = - 2

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c)

5 x - 4 ( 7 x - 3 ) + 17 = 6 ( 9 x - 7 ) - 3 ( 8 x + 5 ) - 20

5 x - 28 x + 12 + 17 = 54 x - 42 - 24 x - 15 - 20

- 23 x + 29 = 30 x - 77

- 23 x - 30 x = - 77 - 29

- 53 x = - 106  l  :  ( - 53 )

x = 2

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d)

( 2 x + 9 ) / 3  -  5 ( 2 x + 11 ) / 6 + 9 / 2 = 4 / 3 - ( 3 x + 8 ) / 2

→ aduc fractiile la acelasi numitor comun 6, apoi il elimin impartind relatia la 6

2 ( 2 x + 9 ) - 5 ( 2 x + 11 ) + 27 = 8 - 3 ( 3 x + 8 )

4 x + 18 - 10 x - 55 + 27 = 8 - 9 x - 24

- 6 x - 10 = - 9 x - 16

- 6 x + 9 x = - 16 + 10

3 x = - 6

x = ( - 6 ) : 3

x = - 2