數學問題(中四的)))急急~~~唔識做!!!!!!

1. 4(x/2-1/2)>=x/2+7
2x-2>=x/2+7
4x-4>=x+14
3x>=18
x>=6

2. 5(x+5)>4(x+5)-(1-x)
x+5>-(1-x)
x+5>-1+x
沒有解

4(x/2-1/2)>=x/2+7
2x-2>=x/2+7
1.5x>=7+2
x>=9/1.5
x>=6

5(x+5)>4(x+5)-(1-x)
5x+25>4x+20-1+x
5x-4x-x+25>20-1
25>19
No solution