Question

Resolução de Inequações do 1º grau
a) 2x – 18 > 4x – 38
b) 2x + 2 > 0
c) x – 2 < 0
d) 5x – 10 ≥ 0
e) 3x + 3 ≤ 0
f) 3x−x<−4−8
g) 4x -20 > 12.
h) 8 - 3 (2k-1) < 0.
i) 2x + 1 ≤ x +3
j) 11x + 10 > 80
k) 18x – 3. (2x-1) < 0.
l) 8 - 3 (2k-1) < 0.
m) 2(x – 8 ) ≤ 3x – 30
n) 12x – 20 > -4x + 14
o) -7x +20 ≤ 14x – 3
p) 20x + 3.(9x + 4) ≤ 5. 4x – 6)

Answer 1

Resposta:

Resolução de Inequações do 1º grau

a) 2x – 18 > 4x – 38

2x- 4x > -38 + 18

-2x > -20   .(-1)

2x > 20

x > 20/2

x > 10

b) 2x + 2 > 0

2x > -2

x > -2/2

x > -1

c) x – 2 < 0

x < 2

d) 5x – 10 ≥ 0

5x ≥ 10

x ≥ 10/5

x ≥ 2

e) 3x + 3 ≤ 0

3x ≤ -3

x ≤ -3/3

x ≤ -1

f) 3x−x<−4−8

2x < -12

x < -12/2

x < -6

g) 4x -20 > 12

4x > 12 - 20

4x > -8

x > -8/4

x > -2

h) 8 - 3 (2k-1) < 0

8 - 6k + 3 < 0

-6k < -8 - 3

-6k < -11      .(-1)

6k > 11

k > 11/6

i) 2x + 1 ≤ x +3

2x - x ≤ 3 - 1

x ≤ 2

j) 11x + 10 > 80

11x > 80 - 10

11x > 70

x > 70/11

k) 18x – 3. (2x-1) < 0

18x -6 + 3 < 0

18x < 3

x < 3/18      :(3/3)

x < 1/6

l) 8 - 3 (2k-1) < 0.

- 6k + 3 < 0

-6k < -8 - 3

-6k < -11      .(-1)

6k > 11

k > 11/6

m) 2(x – 8 ) ≤ 3x – 30

2x - 16 ≤ 3x - 30

2x-3x ≤ -30 + 16

-x ≤ -14       .(-1)

x ≥ 14

n) 12x – 20 > -4x + 14

12x + 4x > 14 + 20

16x > 34

x > 34/16      :(2/2)

x > 17/8

o) -7x +20 ≤ 14x – 3

-7x -14x ≤ -3 - 20

-21x ≤ -23        .(-1)

21x ≥ 23

x ≥ 23/21

p) 20x + 3.(9x + 4) ≤ 5.(4x – 6)

20x + 27x + 12 ≤ 20x - 30

47x - 20x ≤ -30 - 12

27x ≤ - 42

x ≤ -42/27        :( 3/3)

x ≤ -14/9