數學(inequalities)

1)
x+3>2
x>2-3
x>-1
2)
x-2<3 x<3+2
x<5
3)
2(x+1)>4
2x+2>4
2x>2
x>1
5)
7x-9>9x+7
7x-9x>7+9
-2x>16
x<16/(-2)
x<-8

2012-07-17 15:56:19 補充：
X/2+1>X-2
x/2>x-2-1
x/2>x-1
x>2(x-1)
x>2x-2
-x>-2
x<2

2012-07-17 15:59:37 補充：
sorry 計錯數.
X/2+1>X-2
x/2>x-3
x>2(x-3)
x>2x-6
-X>-6
x<6