m) ( đề bài )
6+2(2x+1) > 2x -1 -12
6+2(2x+1) >2x -13
6 + 4x +2 > 2x -13
4x +8 > 2x - 13
2x +8 > -13
2x > -21
x > - \(\dfrac{21}{2}\)
n) (đề bài)
x+5 - 2(2x+1) ≤ 3(x+3)
x+5 -4x-2 ≤ 3x +9
-3x +3 ≤ 3x +9
3 ≤ 3x +9+3x
3 ≤ 6x +9
3 -9 ≤ 6x
-6 ≤ 6x
-1 ≤ x
x ≥ -1
n) (Đề bài)
2(x+1) > 2x -1 -12
2(x+1) > 2x -13
2x +2 > 2x -13
2> -12
i: =>2x+2>2x-1-12
=>2>-13(luôn đúng)
m: =>6+4x+2>2x-1-12
=>4x+8>2x-13
=>2x>-21
=>x>-21/2