Question

Resolva as equações a seguir:
a) 10y - 5 (1 + y) = 3 (2y - 2) – 20
b) (x-5)/10+(1-2x)/5=(3-x)/4
c) 3-2×(x+3)=x-18

Answer 1

Resposta:

Explicação passo-a-passo:

a)

10y - 5.(1 + y) = 3.(2y - 2) – 20

10y - 5 - 5y = 6y - 6 - 20

5y - 5 = 6y - 26

- 5 + 26 = 6y - 5y

21 = y

y = 21

R.: y = 21

____________________

b)

(x-5)/10 + (1-2x)/5 = (3-x)/4

[2.(x-5) + 4.(1-2x)] /20 = 5.(3-x)/20

2x - 10 + 4 - 8x = 15 - 5x

- 6x - 6 = 15 - 5x

- 6 - 15 = 6x- 5x

- 21 = x

x = - 21

R.: x = - 21

_________

Obs.:

Mmc (10,5,4) = 20

10,5,4: 2

5,5, 2: 2

5, 5, 1: 5

1,1,1

= 2.2.5

= 20

_______________

c)

3 - 2.(x+3)= x-18

3 - 2x - 6 = x - 18

- 3 - 2x = x - 18

- 3 + 18 = x + 2x

15 = 3x

3x = 15

x = 15/3

x = 5

R.: 5