Question

QUESTÃO 05 - Resolva as equações de 1° grau
a) 3x + 5 = 8
b) 3x - 4 = 2x + 1
c) 8x - 10 = 3(x + 5)
d) 7(x - 2) = 5(x + 2)
3x +5 2x+20


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Answer 1

Resposta:

A) X = 1

B) X = 5

C) X = 5

D) X = -2

E) X = 5

F) X = 1

3

Explicação passo-a-passo:

A)

3x + 5 = 8

3x = 8 - 5

3x = 3

X = 1

•••••••••••••••••••••••••

B)

3x - 4 = 2x + 1

3x - 2x = 1 + 4

X = 5

•••••••••••••••••••••••••

C)

8x - 10 = 3 (x + 5)

8x - 10 = 3x + 15

8x - 3x = 15 + 10

5x = 25

X = 5

•••••••••••••••••••••••••

D)

7 (x - 2) = 5 (x + 2)

7 (x + 2) -5 (x + 2) = 0

(7 - 5) X (x + 2) = 0

2 (x + 2) = 0

x + 2 = 0

X = -2

•••••••••••••••••••••••••

E)

3x + 5 = 2x + 20

2 3

3 (3x + 5) = 2 (2x + 20)

9x + 15 = 4x + 40

9x - 4x = 40 - 15

5x = 25

X = 5

•••••••••••••••••••••••••

F)

3 - x = x + 1

8 4

4 (3 - x) = 8 (x + 1)

12 - 4x = 8x + 8

-4x - 8x = 8 - 12

-12x = -4

X=1

3

Alternativo:

X = 0,3

OU

-1

X = 3