Question

exercitiul 7 cat mai repede va rog ma grabesc foarte tare dau coroana​

Answer 1

Răspuns:

Explicație:

a)

7x + 14 > 0

7x > - 14

x > -14/7

x > -2

M∩S = {x E Z / -2 < x ≤ 3}

________________

b)

-1 + 3x  > 2x - 5

3x - 2x  > 1 - 5

x  > -4

M∩S = {x E Z / -4 < x ≤ 3}

_________

c)

4x - 5 ≥ 2x + 9

4x - 2x ≥ 5 + 9

2x ≥ 14

x ≥ 14/2

x ≥ 7

M∩S = ∅ (multimea vida)

___________

d)

3x + 2  > 2(x - 1)

3x + 2  > 2x - 2

3x - 2x  > -2 - 2

x  > - 4

M∩S = {x E Z / -4 < x ≤ 3}

_________

e)

4x - 15 + 3x ≥ 14 - 2x

4x + 3x + 2x ≥ 14 + 15

9x ≥ 29

x ≥ 29/9  > 3

M∩S = ∅

__________

f)

19x + 15 > 3(x + 5)

19x + 15 > 3x + 15

19x - 3x > 15 - 15

16x > 0

x > 0

M∩S = {x E Z / 0 < x ≤ 3}

____________

g)

7(x - 2) ≤ 5(2x + 1) - 22

7x - 14 ≤ 10x + 5 - 22

22 - 14 - 5 ≤ 10x - 7x

3 ≤ 3x

x  ≥ 1

M∩S = {x E Z / 1 ≤ x ≤ 3}

_____________

h)

√3x + 5 ≤ 32 - √12x

√3x + 2√3x ≤ 32 - 5

3√3x ≤ 27

x ≤ 27/3√3

x ≤ 27√3/9

x ≤ 3√3

M∩S = {x E Z / x ≤ 3}

________

i)

√3x ≤ √108 - √27

√108 = √9*4*3 = 6√3

√27 = √9*3 = 3√3

6√3 - 3√3 = 3√3

√3x ≤ 3√3

x ≤ 3

M∩S = {x E Z / x ≤ 3}