x^2-x.\(\sqrt{2}\)-4=0
1) x-\(7\sqrt{x-3}\) -9=0 2) \(\sqrt{x+3}\) =5-\(\sqrt{x-2}\) 3) \(\sqrt{x-4\sqrt{x+4}}\) =3 4) \(\sqrt{8-\dfrac{2}{3}x}-5\sqrt{2}\) =0 5) \(\sqrt{x^2-4x+4}\) =2-x
Giải phương trình :
a.\(x^2+5x^2-3=0\)
b.\(x^2-\left(2\sqrt{3}-1\right)x+4\sqrt{3}-6=0\)
c.\(x^2-6x+9=0\)
d.\(x^2-4\sqrt{3}x-4=0\)
c: \(\Leftrightarrow x-3=0\)
hay x=3
Rút gọn biểu thức:
a) \(\dfrac{\sqrt{x^2+4x+4}}{x-1}\)
b) \(x-2y-\sqrt{x^2-4xy+4y^2}\) ( x>= 0; y>=0)
c) \(\dfrac{\sqrt{x^2+4x+4}}{x^2-4}\)
d) \(\dfrac{\sqrt{x^2+4x+4}}{x^2-2}\)
a: \(=\dfrac{\left|x+2\right|}{x-1}\)
b: \(=x-2y-\left|x-2y\right|\)\(=\left[{}\begin{matrix}x-2y-x+2y=0\\x-2y+x-2y=2x-4y\end{matrix}\right.\)
c: \(=\dfrac{\left|x+2\right|}{\left(x+2\right)\left(x-2\right)}=\pm\dfrac{1}{x-2}\)
1, \(\sqrt{x-1}+\sqrt{x-4}=5\)
2, \(2x-7\sqrt{x}+5=0\)
3, \(\sqrt{2x+1}+\sqrt{x-3}=2\sqrt{x}\)
4, \(x-4\sqrt{x}+2021\sqrt{x-4}+4=0\)
5, \(\sqrt{2x-3}-\sqrt{x+1}=7\left(4-x\right)\)
1. ĐKXĐ: $x\geq 4$
PT $\Leftrightarrow \sqrt{x-1}=5-\sqrt{x-4}$
$\Rightarrow x-1=25+x-4-10\sqrt{x-4}$
$\Leftrightarrow 22=10\sqrt{x-4}$
$\Leftrightarrow 2,2=\sqrt{x-4}$
$\Leftrightarrow 4,84=x-4\Leftrightarrow x=8,84$
(thỏa mãn)
2. ĐKXĐ: $x\geq 0$
PT $\Leftrightarrow (2x-2\sqrt{x})-(5\sqrt{x}-5)=0$
$\Leftrightarrow 2\sqrt{x}(\sqrt{x}-1)-5(\sqrt{x}-1)=0$
$\Leftrightarrow (\sqrt{x}-1)(2\sqrt{x}-5)=0$
$\Leftrightarrow \sqrt{x}-1=0$ hoặc $2\sqrt{x}-5=0$
$\Leftrightarrow x=1$ hoặc $x=\frac{25}{4}$ (tm)
3. ĐKXĐ: $x\geq 3$
Bình phương 2 vế thu được:
$3x-2+2\sqrt{(2x+1)(x-3)}=4x$
$\Leftrightarrow 2\sqrt{(2x+1)(x-3)}=x+2$
$\Leftrightarrow 4(2x+1)(x-3)=(x+2)^2$
$\Leftrightarrow 4(2x^2-5x-3)=x^2+4x+4$
$\Leftrightarrow 7x^2-24x-16=0$
$\Leftrightarrow (x-4)(7x+4)=0$
Do $x\geq 3$ nên $x=4$
Thử lại thấy thỏa mãn
Vậy $x=4$
4. ĐKXĐ: $x\geq 4$
PT $\Leftrightarrow (x-4\sqrt{x}+4)+2021\sqrt{x-4}=0$
$\Leftrightarrow (\sqrt{x}-2)^2+2021\sqrt{x-4}=0$
Ta thấy, với mọi $x\geq 4$ thì:
$(\sqrt{x}-2)^2\ge 0$
$2021\sqrt{x-4}\geq 0$
Do đó để tổng của chúng bằng $0$ thì:
$\sqrt{x}-2=\sqrt{x-4}=0$
$\Leftrightarrow x=4$ (tm)
a) 1/2 * sqrt(x - 1) - sqrt(4x - 4) + 3 = 0 c) sqrt(7 - x + 1) = x b) sqrt(x ^ 2 - 4x + 4) + x - 2 = 0
a: ĐKXĐ: x>=1
\(\dfrac{1}{2}\sqrt{x-1}-\sqrt{4x-4}+3=0\)
=>\(3+\dfrac{1}{2}\sqrt{x-1}-2\sqrt{x-1}=0\)
=>\(3-\dfrac{3}{2}\sqrt{x-1}=0\)
=>\(\dfrac{3}{2}\sqrt{x-1}=3\)
=>\(\sqrt{x-1}=2\)
=>x-1=4
=>x=5(nhận)
b: \(\sqrt{x^2-4x+4}+x-2=0\)
=>\(\sqrt{\left(x-2\right)^2}=-x+2\)
=>|x-2|=-(x-2)
=>x-2<=0
=>x<=2
c:
ĐKXĐ: 7-x>=0
=>x<=7
\(\sqrt{7-x}+1=x\)
=>\(\sqrt{7-x}=x-1\)
=>\(\left\{{}\begin{matrix}x-1>=0\\7-x=x^2-2x+1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}1< =x< =7\\x^2-2x+1-7+x=0\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}1< =x< =7\\x^2-x-6=0\end{matrix}\right.\Leftrightarrow x=3\)
\(x^2-5x+14-4\sqrt{x+1}=0\Leftrightarrow(x^2-4x+4)-(x+1-2.2.\sqrt{x+1}+4)+6=0\Leftrightarrow(x-2)^2-(\sqrt{x+1}-2)^2+6=0\Leftrightarrow tính\)
Giải các phương trình sau:
1) \(\sqrt{3x^2+5x+8}-\sqrt{3x^2+5x+1}=1\)
2) \(x^2-2x-12+4\sqrt{\left(4-x\right)\left(2+x\right)}=0\)
3) \(3\sqrt{x}+\dfrac{3}{2\sqrt{x}}=2x+\dfrac{1}{2x}-7\)
4) \(\sqrt{x}-\dfrac{4}{\sqrt{x+2}}+\sqrt{x+2}=0\)
5)\(\left(x-7\right)\sqrt{\dfrac{x+3}{x-7}}=x+4\)
6) \(2\sqrt{x-4}+\sqrt{x-1}=\sqrt{2x-3}+\sqrt{4x-16}\)
7) \(\sqrt{x+2\sqrt{x-1}}+\sqrt{x-2\sqrt{x-1}}=\dfrac{x+3}{2}\)
Giúp mình với ajk, mink đang cần gấp
Điều kiện: \(2\le x\le4\)
\(\Leftrightarrow2\sqrt{x-2}-2\sqrt{2}+\sqrt{4-x}-\left(x^2-8x+16\right)=0\)
\(\Leftrightarrow\sqrt{4x-8}-2\sqrt{2}+\sqrt{4-x}-\left(4-x\right)^2=0\)
\(\Leftrightarrow\frac{-4\left(4-x\right)}{\sqrt{4x-8}+2\sqrt{2}}+\sqrt{4-x}-\left(4-x\right)^2=0\)
\(\Leftrightarrow\sqrt{4-x}\left(\frac{-4\sqrt{4-x}}{\sqrt{4x-8}+2\sqrt{2}}+1-\sqrt{4-x}^3\right)=0\)
\(\Rightarrow\sqrt{4-x}=0\Rightarrow x=4\left(tmdk\right)\) hoặc \(\left(.......\right)=0\)vô nghiệm thì phải
Vậy nghiệm là x=4
a : \(\dfrac{3}{\sqrt{x}-5}+\dfrac{20-2\sqrt{x}}{x-25}\)với x ≥ 0 x ≠ 25
b : \(\dfrac{\sqrt{x}}{\sqrt{x}-3}+\dfrac{2\sqrt{x}-2}{x-9}\)với x ≥ 0 x ≠ 9
c : \(\dfrac{\sqrt{x}-1}{\sqrt{x}+2}+\dfrac{5\sqrt{x}-2}{x-4}\)với x ≥ 0 x ≠ 4
d : \(\left(\dfrac{x-2}{x+2\sqrt{x}}+\dfrac{1}{\sqrt{x}+2}\right).\dfrac{\sqrt{x}+1}{\sqrt{x}-1}\)với ≥ 0 x ≠ 1
\(a,\dfrac{3}{\sqrt{x}-5}+\dfrac{20-2\sqrt{x}}{x-25}\\ =\dfrac{3}{\sqrt{x}-5}+\dfrac{20-2\sqrt{x}}{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}\\ =\dfrac{3\left(\sqrt{x}+5\right)}{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}+\dfrac{20-2\sqrt{x}}{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}\\ =\dfrac{3\sqrt{x}+15+20-2\sqrt{x}}{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}\\ =\dfrac{\sqrt{x}+35}{\left(\sqrt{x}-5\right)\left(\sqrt{x}+5\right)}\)
\(b,\dfrac{\sqrt{x}}{\sqrt{x}-3}+\dfrac{2\sqrt{x}-2}{x-9}\\ =\dfrac{\sqrt{x}}{\sqrt{x}-3}+\dfrac{2\sqrt{x}-2}{x-9}\\ =\dfrac{\sqrt{x}\left(\sqrt{x}+3\right)}{x-9}+\dfrac{2\sqrt{x}-2}{x-9}\\ =\dfrac{x+3\sqrt{x}+2\sqrt{x}-2}{x-9}\\ =\dfrac{x-5\sqrt{x}-2}{x-9}\)
a: \(\dfrac{3}{\sqrt{x}-5}+\dfrac{20-2\sqrt{x}}{x-25}\)
\(=\dfrac{3\sqrt{x}+15+20-2\sqrt{x}}{x-25}=\dfrac{\sqrt{x}+35}{x-25}\)
b: \(\dfrac{\sqrt{x}}{\sqrt{x}-3}+\dfrac{2\sqrt{x}-2}{x-9}\)
\(=\dfrac{x+3\sqrt{x}+2\sqrt{x}-2}{x-9}=\dfrac{x+5\sqrt{x}-2}{x-9}\)
c: \(\dfrac{\sqrt{x}-1}{\sqrt{x}+2}+\dfrac{5\sqrt{x}-2}{x-4}\)
\(=\dfrac{\left(\sqrt{x}-1\right)\left(\sqrt{x}-2\right)+5\sqrt{x}-2}{x-4}\)
\(=\dfrac{x-3\sqrt{x}+2+5\sqrt{x}-2}{x-4}=\dfrac{x+2\sqrt{x}}{x-4}\)
\(=\dfrac{\sqrt{x}}{\sqrt{x}-2}\)
d: \(\left(\dfrac{x-2}{x+2\sqrt{x}}+\dfrac{1}{\sqrt{x}+2}\right)\cdot\dfrac{\sqrt{x}+1}{\sqrt{x}-1}\)
\(=\dfrac{x-2+\sqrt{x}}{\sqrt{x}\left(\sqrt{x}+2\right)}\cdot\dfrac{\sqrt{x}+1}{\sqrt{x}-1}\)
\(=\dfrac{\left(\sqrt{x}+2\right)\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}{\sqrt{x}\left(\sqrt{x}+2\right)\left(\sqrt{x}-1\right)}=\dfrac{\sqrt{x}+1}{\sqrt{x}}\)
( \(\dfrac{\sqrt{x}}{\sqrt{x}-2}\) + \(\dfrac{\sqrt{x}-1}{\sqrt{x}+2}\) - \(\dfrac{3\sqrt{x}+2}{x-4}\) ) : \(\dfrac{\sqrt{x}-2}{x-4}\) ( với x ≥ 0; x ≠ 4)
RÚT GỌN Ạ
Với \(x\ge0;x\ne4\)
\(=\dfrac{\sqrt{x}\left(\sqrt{x}+2\right)+\left(\sqrt{x}-1\right)\left(\sqrt{x}-2\right)-3\sqrt{x}+2}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}.\dfrac{x-4}{\sqrt{x}-2}\)
\(=\dfrac{x+2\sqrt{x}+x-2\sqrt{x}-\sqrt{x}-2-3\sqrt{x}+2}{x-4}.\dfrac{x-4}{\sqrt{x}-2}\)
\(=\dfrac{2x-4\sqrt{x}}{x-4}.\dfrac{x-4}{\sqrt{x}-2}\)
\(=\dfrac{2\sqrt{x}\left(\sqrt{x}-2\right)}{\sqrt{x}-2}=2\sqrt{x}\)