急!F5 inequalities unknown唔明?

請詳細講解以下三條問題 :
(不要網址回答)

Solve each of the following quadratic inequalities graphically and represent the solutions on the number line :

1. 3x-17<4 or 14+4x>-3x
3x<21 or 14>-7x
x<7 or 2<x
我計到答案 : x<7 or 2<x 但點解是: any real number ?

2. 8x-(3x-2)=>7 or 3x-11<=13-3x
5x=>5 or 6x<=24
x=>1 or x<=4
我計到答案 : x=>1 or x<=4 但點解是: any real number ?

3. 2x+5=>4x-3 or 6x+7<=-3x-2
8=>2x or 9x<=-9
x<=4 or x<=-1 點解這條不用any real number ?