Giải BPT:
1. (2 - x)(3x² - 10x + 3) < 0
Giải bpt
3x3 -x2 - 10x > 0
\(x\left(3x^2-x-10\right)>0\)
\(3\left(x^2-2\times x\times\frac{1}{6}+\frac{1}{36}-\frac{1}{36}-10\right)>0\)
\(\left(x-\frac{1}{6}\right)^2>\frac{359}{36}\)
\(\left|x-\frac{1}{6}\right|>\frac{\sqrt{359}}{6}\)
*Th1: \(x>\frac{\sqrt{359}+1}{6}\)
*Th2: \(x< -\frac{\sqrt{359}+1}{6}\)
\(3x^3-x^2-10x>0\)
=> \(x\left(3x^2-x-10\right)>0\)
=> \(x\left(x-2\right)\left(x+\frac{5}{3}\right)>0\)
Ta có TH1 :
\(\hept{\begin{cases}x>0\\x-2>0\\x+\frac{5}{3}>0\end{cases}}=>\hept{\begin{cases}x>0\\x>2\\x>\frac{-5}{3}\end{cases}}\)
TH2 :
\(\hept{\begin{cases}x>0\\x-2< 0\\x+\frac{5}{3}< 0\end{cases}}=>\hept{\begin{cases}x>0\\x< 2\\x< \frac{-5}{3}\end{cases}}\)
TH3 :
\(\hept{\begin{cases}x< 0\\x-2< 0\\x+\frac{5}{3}>0\end{cases}=>\hept{\begin{cases}x< 0\\x< 2\\x>\frac{-5}{3}\end{cases}}}\)
TH4 :
\(\hept{\begin{cases}x< 0\\x-2>0\\x+\frac{5}{3}< 0\end{cases}=>\hept{\begin{cases}x< 0\\x>2\\x< \frac{-5}{3}\end{cases}}}\)
Dài thiệt đó bạn
\(x\left(3x^2-x-10\right)>0\)
\(3\left(x^2-2\times x\times\frac{1}{6}+\frac{1}{36}-\frac{1}{36}-10\right)>0\)
\(\left(x-\frac{1}{6}\right)^2>\frac{359}{36}\)
\(\left|x-\frac{1}{6}\right|>\frac{\sqrt{359}}{6}\)
Giải BPT sau :
a) (5x + 2)(10x +3)(x - 6) < 0 b) (3-x)(x+4)(15+x) >0
c) (x+2)(x+3)(x+4)>0 d) (3x+4)(2x+2)(7-x)
Giải bpt: (x-3)(x+1(2-3x)>0
\(\left(x-3\right)\left(x+1\right)\left(2-3x\right)>0.\)
\(x\) | \(-\infty\) \(-1\) \(\dfrac{2}{3}\) \(3\) \(+\infty\) |
\(x-3\) | - | - | - 0 - |
\(x+1\) | - 0 + | + | + |
\(2-3x\) | + | + 0 - | - |
\(\left(x-3\right)\left(x+1\right)\left(2-3x\right).\) | + 0 - 0 + 0 + |
Vậy \(\left(x-3\right)\left(x+1\right)\left(2-3x\right)>0\) khi \(x\in\left(-\infty;-1\right)\cup\left(\dfrac{2}{3};3\right)\cup\left(3;+\infty\right).\)
Giải bpt: (x2 + 5)(2x + 3)(3x - 1) < 0
\(\left(x^2+5\right)\left(2x+3\right)\left(3x-1\right)< 0\)
Do \(\left(x^2+5\right)>0\)
\(\Rightarrow bpt\Leftrightarrow\left(2x+3\right)\left(3x-1\right)< 0\)
\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}2x+3>0\\3x-1< 0\end{matrix}\right.\\\left\{{}\begin{matrix}2x+3< 0\\3x-1>0\end{matrix}\right.\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x>\frac{-3}{2}\\x< \frac{1}{3}\end{matrix}\right.\\\left\{{}\begin{matrix}x< \frac{-3}{2}\\x>\frac{1}{3}\end{matrix}\right.\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}\frac{-3}{2}< x< \frac{1}{3}\left(chon\right)\\\frac{1}{3}< x< \frac{-3}{2}\left(loai\right)\end{matrix}\right.\)
Vậy...
giải các bpt sau :
a) \(-4\le\frac{x^2-2x-7}{x^2+1}\le1\)
b) \(-1< \frac{10x^2-3x-2}{-x^2+3x-2}< 1\)
giúp mình giải bpt vs
\(\dfrac{\left|2x-1\right|-x}{2x}>1;\dfrac{2-\left|x-2\right|}{x^2-1}\ge0;\dfrac{\sqrt{x+4}-2}{4-9x^2}\le0;\dfrac{x^2-2x-3}{\sqrt[3]{3x-1}+\sqrt[3]{4-5x}}\ge0;\)\(3x^2-10x+3\ge0;\left(\sqrt{2}-x\right)\left(x^2-2\right)\left(2x-4\right)< 0;\dfrac{1}{x+9}-\dfrac{1}{x}>\dfrac{1}{2};\dfrac{2}{1-2x}\le\dfrac{3}{x+1}\)
giải bpt :
a)\(\frac{x^3-4x^2+5x}{x^3-x^2-10x-8}>0\)
b)\(4x^2-4x+1>9\)
giải các bpt sau
a,\(\dfrac{x^2+2x-13}{x-1}< 1\)
b,\(\dfrac{3x^2+x-4}{x-1}< 3\)
c,\(\dfrac{2x^2-3x+1}{x+2}>0\)
d,\(\dfrac{x^2-x-6}{x^2-1}\le1\)
a: =>\(\dfrac{x^2+2x-13-x+1}{x-1}< 0\)
=>\(\dfrac{x^2+x-12}{x-1}< 0\)
=>\(\dfrac{\left(x+4\right)\left(x-3\right)}{x-1}< 0\)
=>1<x<3 hoặc x<-4
b: =>\(\dfrac{3x^2+4x-3x-4}{x-1}< 3\)
=>3x+4<3
=>3x<-1
=>x<-1/3
c: TH1: 2x^2-3x+1>0 và x+2>0
=>(2x-1)(x-1)>0 và x+2>0
=>x>1
TH2: (2x-1)(x-1)<0 và x+2<0
=>x<-2 và 1/2<x<1
=>Loại
Giải bpt 3x²+11x+4-4(x+1)√(2x+1)-2(x-1)√x >= 0