a: x-2>4x+5
=>4x+5<x-2
=>3x<-7
hay x<-7/3
b: 3x-1<3+2(x+1)
=>3x-1<3+2x+2
=>3x-1<2x+5
=>x<6
c: 3x+4>2x+3
=>3x-2x>3-4
=>x>-1
d: 4x-8>=3(3x-1)
=>4x-8>=9x-3
=>-5x>=5
hay x<=-1
\(a,x-2>4x+5\)
\(\Leftrightarrow x-2-4x-5>0\)
\(\Leftrightarrow-3x-7>0\)
\(\Leftrightarrow-3x>7\)
\(\Leftrightarrow x< -\dfrac{7}{3}\)(Chia số âm,BPT đổi dấu)
\(b,3x-1< 3+2\left(x+1\right)\)
\(\Leftrightarrow3x-1-3-2x-2< 0\)
\(\Leftrightarrow x-6< 0\)
\(\Leftrightarrow x< 6\)
\(c,3x+4>2x+3\)
\(\Leftrightarrow3x+4-2x-3>0\)
\(\Leftrightarrow x+1>0\)
\(\Leftrightarrow x>-1\)
\(d,4x-8\ge3\left(3x-1\right)\)
\(\Leftrightarrow4x-8-9x+3\ge0\)
\(\Leftrightarrow-5x-5\ge0\)
\(\Leftrightarrow-5x\ge5\)
\(\Leftrightarrow x\le-1\) (Chia số âm,BPT đổi dấu)
giúp mik với mn ơi 
