a) `5-2(x+1) > 1+x`
⇔`5-2x+2 > 1+x`
⇔`-2x-x > 1-5-2`
⇔`-x > -6`
⇔`x < 6`
Vậy `S={x|x<6}`
---------|-------------)----------------->
`0` `6`
b) `(x-3)(x+3) < (x+2)^2+3`
⇔`x^2-9 < x^2+4x+4+3`
⇔`x^2-x^2-4x < 4+3+9`
⇔`-4x < 16`
⇔` x > -4`
Vậy `S={x|x > -4}`
-----(----------|----------->
`-4` `0`
c) `(2x+1)/(5)-(2x-2)/(3) < 1`
⇔3(2x+1)-5(2x-2) < 1`
⇔`6x+3-10x+10 < 1`
⇔`-4x < 1-10-3`
⇔`-4x < -12`
⇔`x > 3`
Vậy `S={x|x>3}`
-----------|-------(--------------->
`0` `3`
c) `(3x-5)/(8)+(1-5x)/(4) < 1/2`
⇔`3x-5+2(1-5x) < 1/2`
⇔`3x-5+2-10x < 1/2`
⇔`-7x < 1/2-2+5`
⇔`-7x < 7/2`
⇔`x > -1/2`
Vậy `S={x|x>-1/2}`
------(----------|----------->
`-1/2` `0`
