Question

Exercitiul 7 Va rog eu frumos.​

Answer 1

$x + 11 \geqslant 7 = > x \geqslant 7 - 11 = > x \geqslant - 4$

$x - 3 \leqslant 1 = > x \leqslant 1 + 3 = > x \leqslant 4$

$7 - x < 4 = > - x < 4 - 7 = > - x < - 3 = > x > 3$

$- x < 6 = > - 1 \times ( - x) > - 1 \times 6 = > x > - 6$

$- x \geqslant - 2 = > - 1 \times ( - x ) \leqslant - 1 \times ( - 2) = > x \leqslant 2$

$- x < 0 = > - 1 \times ( - x) > - 1 \times 0 = > x > 0$

Answer 2

a) x+11≥7 |-11

x≥-4 => x={-4,-3,-2...}

b)x-3≤1 |+3

x≤4 => x={ 4,3,2,1,...}

c)7-x<4 |+x

7<x+4 |-4

3<x => x={4,5,6...}

d)2x≤-8|:2

x≤4 => x={ 4,3,2,1...}

e)-x<6 => x={-1,-2,-3,-4,...}

f)-x ≥-2 |:(-1)

x≥2 => x={2,3,4,5,...}

g)-x<0 => x={-1,-2,-3,...}

h)-x≥0 => -x={∅}