Question

Resolva as equações
a) 3+ 7x = -39 *



5x -3 =2x+5 *



5x - 3 = 9 - x *



4x - 12 = 12x + 4



20 - x = 25 + 4x *



7x + 8 = -3x + 9 *



Por favor me ajudem!


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Answer 1

Resposta:

3+ 7x = -39 *

7x = - 39 - 3

7x = - 42

x = -42/7

x = - 6

5x - 3 = 2x + 5 *

5x - 2x = 5 + 3

3x = 8

x = 8/3

x = 2.6666666667

5x - 3 = 9 - x *

5x + x = 9 + 3

6x = 12

x = 12/6

x = 2

4x - 12 = 12x + 4

4x - 12x = 4 + 12

-8x = 16 . (-1)

8x = - 16

x = -16/8

x = -2

20 - x = 25 + 4x *

- x - 4x = 25 - 20

-5x = 5 . (-1)

5x = -5

x = -5/5

x = -1

7x + 8 = -3x + 9 *

7x + 3x = 9 - 8

10x = 1

x = 1/10

x = 0.1