\(\sqrt{x-2}=\dfrac{2}{3}\)
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ĐK:x>=2
Căn[(x-2)(x-1)] + Căn(x+3) = Căn(x-2) + Căn[(x-1)(x-3)]
[Căn(x-1)-1]×[Căn(x-2)-Căn(x+3)=0
TH1: Căn(x-1)-1=0
<=> Căn(x-1)=1
=> x-1=1
=> x=2 (TM)
TH2: Căn(x-2)-Căn(x+3)=0
=> x-2+2Căn[(x-2)(x+3)]+x+3=0
<=> 2x+1=2Căn[(x-2)(x+3)
=> 4x2+4x+1=4(x-2)(x+3)
<=> 4x2+4x+1=4x2+4x-24
<=> 0x=-25(vô lý)
Vậy pt có 1 nghiệm là x=2
\(\sqrt{x^2-3x+2}\)+\(\sqrt{x+3}\)=\(\sqrt{x-2}\)+\(\sqrt{x^2+2x-3}\)(dkxd x>2)
<=>\(\sqrt{\left(x-1\right)\left(x-2\right)}+\sqrt{x+3}\)=\(\sqrt{x-2}+\sqrt{\left(x+3\right)\left(x-1\right)}\)
<=>\(\sqrt{x-1}\left(\sqrt{x-2}-\sqrt{x-3}\right)-\left(\sqrt{x-2}-\sqrt{x-3}\right)=0\)
< =>\(\left(\sqrt{x-1}-1\right)\left(\sqrt{x-2}-\sqrt{x-3}\right)=0\)
den day tu lam nha ban
\(R=\left(\dfrac{3\sqrt{x}}{\sqrt{x}+2}+\dfrac{\sqrt{x}}{\sqrt{x}-2}-\dfrac{3x-5\sqrt{x}}{4-x}\right):\left(\dfrac{2\sqrt{x}-1}{\sqrt{x}-2}-1\right)\left(ĐK:x\ge0,x\ne4\right)\\ =\left(\dfrac{3\sqrt{x}}{\sqrt{x}+2}+\dfrac{\sqrt{x}}{\sqrt{x}-2}+\dfrac{3x-5\sqrt{x}}{\sqrt{x}^2-2^2}\right):\dfrac{2\sqrt{x}-1-\left(\sqrt{x}-2\right)}{\sqrt{x}-2}\)
\(=\dfrac{3\sqrt{x}\left(\sqrt{x}-2\right)+\sqrt{x}\left(\sqrt{x}+2\right)+3x-5\sqrt{x}}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}.\dfrac{\sqrt{x}-2}{2\sqrt{x}-1-\sqrt{x}+2}\\ =\dfrac{3x-6\sqrt{x}+x+2\sqrt{x}+3x-5\sqrt{x}}{\sqrt{x}+2}.\dfrac{1}{\sqrt{x}+1}\)
\(=\dfrac{7x-9\sqrt{x}}{\left(\sqrt{x}+2\right)\left(\sqrt{x}+1\right)}\)
Bạn xem lại đề nhé, rút gọn thường ra kết quả rất đẹp chứ không dài như kết quả này đâu ạ.
a) Ta có: \(M=\left(\dfrac{\sqrt{x}-3}{\sqrt{x}-2}-\dfrac{\sqrt{x}+1}{\sqrt{x}+3}\right)\cdot\dfrac{x+3\sqrt{x}}{7-\sqrt{x}}\)
\(=\left(\dfrac{\left(\sqrt{x}-3\right)\left(\sqrt{x}+3\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+3\right)}-\dfrac{\left(\sqrt{x}+1\right)\left(\sqrt{x}-2\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+3\right)}\right)\cdot\dfrac{\sqrt{x}\left(\sqrt{x}+3\right)}{7-\sqrt{x}}\)
\(=\dfrac{x-9-\left(x-2\sqrt{x}+\sqrt{x}-2\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+3\right)}\cdot\dfrac{\sqrt{x}\left(\sqrt{x}+3\right)}{7-\sqrt{x}}\)
\(=\dfrac{x-9-x+\sqrt{x}+2}{\left(\sqrt{x}-2\right)}\cdot\dfrac{1}{-\left(\sqrt{x}-7\right)}\)
\(=\dfrac{\sqrt{x}-7}{\sqrt{x}-2}\cdot\dfrac{-1}{\sqrt{x}-7}\)
\(=\dfrac{-1}{\sqrt{x}-2}\)(1)
b) Ta có: \(x^2-4x=0\)
\(\Leftrightarrow x\left(x-4\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x-4=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\left(nhận\right)\\x=4\left(loại\right)\end{matrix}\right.\)
Thay x=0 vào biểu thức (1), ta được:
\(M=\dfrac{-1}{\sqrt{0}-2}=\dfrac{-1}{-2}=\dfrac{1}{2}\)
Vậy: Khi \(x^2-4x=0\) thì \(M=\dfrac{1}{2}\)
\(A=\sqrt{\left(\dfrac{1}{2}-x\right)^2+\left(\dfrac{\sqrt{11}}{2}\right)^2}+\sqrt{\left(\dfrac{1}{2}+x\right)^2+\left(\dfrac{\sqrt{11}}{2}\right)^2}\)
\(\ge\sqrt{\left(\dfrac{1}{2}-x+\dfrac{1}{2}+x\right)^2+\left(\dfrac{\sqrt{11}}{2}+\dfrac{\sqrt{11}}{2}\right)^2}\)
\(=\sqrt{12}\)
"=" xảy ra khi x = 0
cậu cho mk xin link facebook của jonathan galindo đi rồi mk sẽ trả lời câu hỏi của cậu
\(\sqrt{x-2}\) = \(\dfrac{2}{3}\) (đk \(x-2\) ≥ 0; \(x\ge\) 2)
\(x-2\) =(\(\dfrac{2}{3}\))2
\(x-2\) = \(\dfrac{4}{9}\)
\(x=\dfrac{4}{9}\) + 2
\(x=\dfrac{22}{9}\)
Vậy \(x=\dfrac{22}{9}\)
ĐKXĐ: \(x\ge2\)
\(\sqrt{x-2}=\dfrac{2}{3}\)
\(x-2=\dfrac{4}{9}\)
\(x=\dfrac{4}{9}+2\)
\(x=\dfrac{22}{9}\) (nhận)
Vậy \(x=\dfrac{22}{9}\)