Question

AJUDA POR FAVOOR SCRR

Calcule o valor da incógnita nas equações abaixo​

Answer 1

Explicação passo-a-passo:

a)

$4x + 12 = 20 \\ 4x = 20 - 12 \\ 4x = 8 \\ x = \frac{8}{4} \\ \\ x = 2$

b)

$10x - 5 = 2x + 8 \\ 10x - 2x = 8 + 5 \\ 8x = 13 \\ x = \frac{13}{8} \\c) 10 - 2x - 6 = 8 + 6x + 15 \\ - 2x - 6x = 8 + 15 - 10 + 6 \\ - 8x =19 \: \: \: \cdot( - 1)\\ 8x = - 19 \\ x = - \frac{19}{8}$

d)

$2(3x) - 5 = 10x - 4 \\ 6x - 5 = 10x - 4 \\ 6x - 10x = - 4 + 5 \\ - 4x = 1 \: \: \: .( - 1) \\ 4x = - 1 \\ x = - \frac{1}{4}$

Answer 2

Resposta:

a) 4(x+3) = 20

4x+12 = 20

4x = 20 - 12

4x = 8

x = $\frac{8}{4}$

x = 2

b) 5 (2x-1) = 2 (x+4)

10x-5 = 2x+8

10x-2x = 8 + 5

8x = 13

x = $\frac{13}{8}$

x = 1,625

c) 10 - 2 (x+3) = 8 + 3 (2x + 5)

10 - (2x + 6) = 8 + 6x + 15

10 - 2x - 6 = 8 + 6x + 15

4 - 15 - 8 = 6x + 2x

- 19 = 8x

x = $\frac{-19}{8}$

x = -2,375

d) $\frac{3x}{5} - \frac{1}{2} = x - \frac{2}{5}$

$\frac{6x-5 }{10} = \frac{10x-4}{10}$

6x - 5 = 10x - 4

6x - 10x = -4 + 5

-4x = 1 . (-1)

4x = -1

x = $\frac{-1}{4}$

x = -0,25

e) $\frac{x}{2} +\frac{3}{4} = \frac{2x}{6} - \frac{1}{3}$

$\frac{6x+ 9}{12} = \frac{4x-4}{12}$

6x + 9 = 4x - 4

6x - 4x = -4 - 9

2x = -13

x = $\frac{-13}{2}$

x = - 6,5

f)$\frac{3y}{2} - 1 = \frac{3}{4} - 2y$

$\frac{6y-4}{4} = \frac{3 - 8y}{4}$

6y - 4 = 3 - 8y

6y + 8y = 3 + 4

14y = 7

y = $\frac{7}{14}$

y = $\frac{1}{2}$

y = 0,5

g) x + 5 = 21

x = 21 - 5

x = 16

h) 2 (x+3) = 30

2x + 6 = 30

2x = 30 - 6

2x = 24

x = $\frac{24}{2}$

x = 12

i) 8 - 2 (x + 5) = 5

8 - 2x - 10 = 5

- 2x = 5 - 8 + 10

-2x = 7 . (-1)

2x = -7

x = $\frac{-7}{2}$

x = -3,5

j) 3 (y-1) - 4 (y-2) = 6

3y - 3 - 4y + 8 = 6

-y = 6 - 8 + 3

-y = -1 . (-1)

y = 1

Explicação passo a passo: