Question

30 pontos para quem responder


1- Resolva as equações polinomiais de 1º grau a seguir:

a) 2 (x − 2) = 3 (x + 2)


b) 3x − 5 = 9x + 7


c) x − 9 = 3x + 5


d) 9x − 13 = 2 (x − 3)


e) − 2x + 3 = 0


f) f (x) =− 6x + 18


g) f (x) =− 2x + 1


h)

X
_ + 3 (− x + 2) = 3 + 2

2

Answer 1

a) 2( x -2) = 3 ( x +2)

2x -4 = 3x +6

2x -3x = 6 +4

-x = 10

x = 10

b) 3x − 5 = 9x + 7

3x - 9x = 7 + 5

-6x = 12

-x = 12 ÷ 6

-x = 2

x = -2

c) x − 9 = 3x + 5

x - 3x = 5 + 9

- 2x = 14

-x = 14 ÷ 2

-x = 7

x = -7

d) 9x − 13 = 2 (x − 3)

9x - 13 = 2x - 6

9x - 2x = -6 + 13

7x = 7

x = 7 ÷ 7

x = 1

e) − 2x + 3 = 0

-2x = -3

-x = -3 ÷ 2

-x = -1,5

x = 1,5

f) f (x) =− 6x + 18

-6x = -18

-x = -18 ÷ 6

-x = -3

x = 3

g) f (x) =− 2x + 1

-2x = -1

-x = -1 ÷ 2

-x = -0,5

x = 0,5

h) x/2 + 3 (− x + 2) = 3 + 2

x/2 - 3x +6 = 5

x/2 - 6x/2 + 12/2 = 10/2

x - 6x + 12 = 10

-5x = 10 - 12

-5x = -2

-x = -2 ÷ 5

-x = -0,4

x = 0,4