Giải bpt: x^2 - 4 > 0
Giải bpt 3x²+11x+4-4(x+1)√(2x+1)-2(x-1)√x >= 0
giải bpt: x^4-4x^3+x^2+6x+2<0
giải BPT sau
a,(4x-1)(x^2+12)(-x+4)>0
b,(2x-1)(5-2x)(1-x)<0
\(a,\left(4x-1\right)\left(x^2+12\right)\left(-x+4\right)>0\)
\(\Leftrightarrow\left[{}\begin{matrix}4x-1>0\\x^2+12>0\left(LD\forall x\right)\\-x+4>0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}4x>1\\-x>-4\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x>\dfrac{1}{4}\\x< 4\end{matrix}\right.\)
Vậy \(S=\left\{x|\dfrac{1}{4}< x< 4\right\}\)
\(b,\left(2x-1\right)\left(5-2x\right)\left(1-x\right)< 0\)
\(\Leftrightarrow\left[{}\begin{matrix}2x-1< 0\\5-2x< 0\\1-x< 0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x< \dfrac{1}{2}\\x>\dfrac{5}{2}\\x< 1\end{matrix}\right.\)
Vậy \(S=\left\{x|1>x>\dfrac{5}{2}\right\}\)
Giải bpt sau:
\(\dfrac{x-1}{4-x}\text{≥}0\)
\(bpt\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x-1\ge0\\4-x>0\end{matrix}\right.\\\left\{{}\begin{matrix}x-1\le0\\4-x< 0\end{matrix}\right.\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x\ge1\\x< 4\end{matrix}\right.\\\left\{{}\begin{matrix}x\le1\\x>4\end{matrix}\right.\end{matrix}\right.\Leftrightarrow1\le x< 4\)
Vậy .......
\(\left[{}\begin{matrix}\left\{{}\begin{matrix}x-1\ge0\\4-x>0\end{matrix}\right.\\\left\{{}\begin{matrix}x-1\le0\\4-x< 0\end{matrix}\right.\end{matrix}\right.\)⇔\(\left[{}\begin{matrix}\left\{{}\begin{matrix}x\ge1\\x< 4\end{matrix}\right.\\\left\{{}\begin{matrix}x\le1\\x>4\end{matrix}\right.\end{matrix}\right.\)
Vậy....
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)
-2*x^2 -7*x+9 <=0 giải bpt
Sau này bạn vào biểu tượng \(\sum\) đánh kí tự cho dễ nhìn nhé!
\(-2x^2-7x+9\le0\Leftrightarrow2x^2+7x-9\ge0\\ \Leftrightarrow\left(x-1\right)\left(2x+9\right)\ge0\\ \Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x-1\ge0\\2x+9\ge0\end{matrix}\right.\\\left\{{}\begin{matrix}x-1\le0\\2x+9\le0\end{matrix}\right.\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x\ge1\\x\ge-\dfrac{9}{2}\end{matrix}\right.\\\left\{{}\begin{matrix}x\le1\\x\le-\dfrac{9}{2}\end{matrix}\right.\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x\ge1\\x\le-\dfrac{9}{2}\end{matrix}\right.\)
Vậy .........
giải bpt
a, x2 - 7x +12 > 0
b, (4 - x ) (5x +1) > (x -4)(2x+3)
giải bpt
\(x^2-1>0\)
\(x^2-1>0\Rightarrow x^2>1\Rightarrow\left|x\right|>1\Rightarrow\left[{}\begin{matrix}x>1\\x< -1\end{matrix}\right.\)
\(\Rightarrow x^2>1\Rightarrow x>1\) hoặc \(x< -1\)
Ta có: \(x^2-1>0\)
\(\Leftrightarrow\left(x-1\right)\left(x+1\right)>0\)
\(\Leftrightarrow\left[{}\begin{matrix}x>1\\x< -1\end{matrix}\right.\)