Respuesta :

mreijepatmat
27) 2x-1≥0 → 2x≥1 → x≥1/2 or x≥0.5


-∞------------------(-2)-------------(-1)------------0------0.5------1------------2----------+∞
                                                                              ×××××××××××××××××××××
                                                                                      this is x≥0.5

28) -4≤2x-3<4; add 3 to each part: 
 -4+3≤2x-3+3<4+3
-1≤2x<7. Divide all parts by 2:

-1/2≤x<7/2   OR -0.5≤x<3.5

-∞------------(-2)---------(-1)-----(-0.5)-----0--------1--------3------(3.5)-----4---------∞
                                                  ××××××××××××××××××××××
                                                  This is -0.5≤x<3.5. It starts at
                                                  -0.5 and it goes until 3.49999999999
                                                   and doesn't reach 3.5

29) x/2 -x/3 >5. But x/2-x/3 = (3x-2x)/6 = x/6, then:

x/2-x/3>5  ↔ x/6>5   OR x>30

-∞-------(-30)----------(-20)-------(-10)------0--------10--------20-------30------------+∞
                                                                                                      ××××××××××
                                                                                                     this is x>30                                                                                                          It starts at 
                                                                                                     30.000001
                                                                                                     and stops +∞
                                                                                                    

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