Jawabanmu

2014-08-31T11:21:40+07:00
X+2<2x+1<3x+7  | dibagi 3

\frac{x}{3} + \frac{2}{3} < \frac{2x}{3} + \frac{1}{3} < x + \frac{7}{3}   |  -x

\frac{-2x}{3} + \frac{2}{3} < \frac{-x}{3} + \frac{1}{3} <  \frac{7}{3}  |  dikali 3

-2x+2 < -x+1 < 7 | Dibagi 2

-x + 1 <  \frac{-x}{2} +  \frac{1}{2} <  \frac{7}{2}



1 2 1
Jawaban paling cerdas!
2014-08-31T11:26:21+07:00
X+2 < 2x+1 < 3x+7
x+2 < 2x+1  dan 2x+ 1<3x+7
x+2+(-2) < 2x +1 +(-2) dan 2x+1+(-1) < 3x+7+(-1)
x<2x-1 dan 2x<3x+6
-x<1  dan -x<6
jadi, x>-1 dan x>-6
HP = {X | -1 < x , x ∈ real}