\(\sqrt{x^2+x-1}+\sqrt{x^2-x+1}=x^2-x+2\)
giải hộ m với
Thu gọn các phân thức sau với x≥0
g)\(\dfrac{\sqrt{x}+3}{x\sqrt{x}+27}\)
h) \(\dfrac{2x-2\sqrt{x}+2}{x\sqrt{x}+1}\)
i)\(\dfrac{x-3\sqrt{x}+2}{x-\sqrt{x}}\)
k) \(\dfrac{x+7\sqrt{x}+12}{x-9}\)
l) \(\dfrac{x+\sqrt{x}-2}{x-2\sqrt{x}+1}\)
giải chi tiết hộ mình với ạ !!!
g: \(\dfrac{\sqrt{x}+3}{x\sqrt{x}+27}=\dfrac{1}{x-3\sqrt{x}+9}\)
h: \(\dfrac{2x-2\sqrt{x}+2}{x\sqrt{x}+1}=\dfrac{2}{\sqrt{x}+1}\)
i: \(\dfrac{x-3\sqrt{x}+2}{x-\sqrt{x}}=\dfrac{\sqrt{x}-2}{\sqrt{x}}\)
k: \(\dfrac{x+7\sqrt{x}+12}{x-9}=\dfrac{\sqrt{x}+4}{\sqrt{x}-3}\)
i: \(\dfrac{x+\sqrt{x}-2}{x-2\sqrt{x}+1}=\dfrac{\sqrt{x}+2}{\sqrt{x}-1}\)
Cho bt: P=\(\dfrac{\sqrt{x}+3}{\sqrt{x}-2}+\dfrac{\sqrt{x}+2}{3-\sqrt{x}}+\dfrac{\sqrt{x}+2}{x-5\sqrt{x}+6}.\left(1-\dfrac{\sqrt{x}}{\sqrt{x}+1}\right)\)
a, Rút gọn P
b, P khi x = 6-2\(\sqrt{5}\)
giải hộ e với e đang cần gấp để đối chiếu kết quả!
a: \(=\dfrac{x-9-x+4}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-3\right)}+\dfrac{\sqrt{x}+2}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-3\right)}\cdot\dfrac{\sqrt{x}}{\sqrt{x}+1}\)
\(=\dfrac{-5\sqrt{x}-5+x+2\sqrt{x}}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-3\right)\left(\sqrt{x}+1\right)}\)
\(=\dfrac{x-3\sqrt{x}-5}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-3\right)\left(\sqrt{x}+1\right)}\)
b: khi x=6-2căn 5 thì \(P=\dfrac{6-2\sqrt{5}-3\sqrt{5}+3-5}{\left(\sqrt{5}-3\right)\left(\sqrt{5}-4\right)\cdot\sqrt{5}}\)
\(=\dfrac{-5\sqrt{5}+4}{\sqrt{5}\left(\sqrt{5}-3\right)\left(\sqrt{5}-4\right)}\)
a: \(\Leftrightarrow\sqrt{6}\left(x+1\right)=5\sqrt{6}\)
=>x+1=5
=>x=4
b: =>x^2/10=1,1
=>x^2=11
=>x=căn 11 hoặc x=-căn 11
c: =>(4x+3)/(x+1)=9 và (4x+3)/(x+1)>=0
=>4x+3=9x+9
=>-5x=6
=>x=-6/5
d: =>(2x-3)/(x-1)=4 và x-1>0 và 2x-3>=0
=>2x-3=4x-4 và x>=3/2
=->-2x=-1 và x>=3/2
=>x=1/2 và x>=3/2
=>Ko có x thỏa mãn
e: Đặt căn x=a(a>=0)
PT sẽ là a^2-a-5=0
=>\(\left[{}\begin{matrix}a=\dfrac{1+\sqrt{21}}{2}\left(nhận\right)\\a=\dfrac{1-\sqrt{21}}{2}\left(loại\right)\end{matrix}\right.\)
=>x=(1+căn 21)^2/4=(11+căn 21)/2
Rút gọn biểu thức sau
P=\(\dfrac{3-\sqrt{x}}{\sqrt{x}-2}+1:\dfrac{\sqrt{x}}{\sqrt{x}-2}-\dfrac{\sqrt{x}+1}{\sqrt{x}+2}+\dfrac{2\sqrt{x}+7}{4-x}\)
giải chi tiết hộ e vs ạ
\(P=\dfrac{3-\sqrt{x}}{\sqrt{x}-2}+\dfrac{\sqrt{x}-2}{\sqrt{x}}-\dfrac{\sqrt{x}+1}{\sqrt{x}-2}+\dfrac{2\sqrt{x}+7}{4-x}\left(x>0;x\ne4\right)\\ P=\dfrac{\left(3-\sqrt{x}\right)\left(\sqrt{x}+2\right)-\left(\sqrt{x}+1\right)\left(\sqrt{x}+2\right)+2\sqrt{x}+7}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}+\dfrac{\sqrt{x}-2}{\sqrt{x}}\\ P=\dfrac{\sqrt{x}+6-x-x-3\sqrt{x}-2+2\sqrt{x}+7}{\left(\sqrt{x}+2\right)\left(\sqrt{x}-2\right)}+\dfrac{\sqrt{x}+2}{\sqrt{x}}\\ P=\dfrac{-2x+11}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}+\dfrac{\sqrt{x}+2}{\sqrt{x}}\\ P=\dfrac{-2x\sqrt{x}+11\sqrt{x}+\left(\sqrt{x}+2\right)\left(x-4\right)}{\sqrt{x}\left(x-4\right)}\)
\(P=\dfrac{-2x\sqrt{x}+11\sqrt{x}+x\sqrt{x}-4\sqrt{x}+2x-8}{\sqrt{x}\left(x-4\right)}\\ P=\dfrac{-x\sqrt{x}+8\sqrt{x}+2x-8}{\sqrt{x}\left(x-4\right)}\)
g)\(\sqrt{-x^2+4x-5}\)
h)\(\sqrt{x^2+2x+2}\)
i)\(\sqrt{\left(x-1\right)\left(x-3\right)}\)
giải chi tiết hộ mình với ạ !!!
g, \(y=\sqrt{-x^2+4x-5}=\sqrt{-\left(x-2\right)^2-1}\)
\(\Rightarrow\) Hàm số này không xác định với mọi x.
h, \(y=\sqrt{x^2+2x+2}=\sqrt{\left(x+1\right)^2+1}>0\forall x\)
\(\Rightarrow\) Hàm số này xác định với mọi x.
i, \(y=\sqrt{\left(x-1\right)\left(x-3\right)}\) xác định khi:
\(\left(x-1\right)\left(x-3\right)\ge0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3\ge0\\x-1\le0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x\ge3\\x\le1\end{matrix}\right.\)
rút gọn biểu thức sau
D=\(\left(\dfrac{\sqrt{x}}{\sqrt{x}+1}+\dfrac{3\sqrt{x}+1}{x-1}\right):\dfrac{\sqrt{x}-2}{\sqrt{x}-1}\)
giải chi tiết hộ mình với ạ!!!
\(D=\left(\dfrac{\sqrt{x}}{\sqrt{x}+1}+\dfrac{3\sqrt{x}+1}{x-1}\right):\dfrac{\sqrt{x}+2}{\sqrt{x}-1}\left(x\ge0;x\ne1\right)\\ D=\dfrac{\sqrt{x}\left(\sqrt{x}-1\right)+3\sqrt{x}+1}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+1\right)}\cdot\dfrac{\sqrt{x}-1}{\sqrt{x}+2}\\ D=\dfrac{\left(\sqrt{x}+1\right)^2}{\sqrt{x}+1}\cdot\dfrac{1}{\sqrt{x}+2}=\dfrac{\sqrt{x}+1}{\sqrt{x}+2}\)
\(\frac{15\sqrt{x}-11}{x+2\sqrt{x}-3}-\frac{3\sqrt{x}-2}{1-\sqrt{x}}-\frac{3}{\sqrt{x}+3}\)
Giải hộ với ạ
ĐKXĐ: \(x\ge0;x\ne1\)
\(\frac{15\sqrt{x}-11}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+3\right)}+\frac{3\sqrt{x}-2}{\sqrt{x}-1}-\frac{3}{\sqrt{x}+3}\)
\(=\frac{15\sqrt{x}-11}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+3\right)}+\frac{\left(3\sqrt{x}-2\right)\left(\sqrt{x}+3\right)}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+3\right)}-\frac{3\left(\sqrt{x}-1\right)}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+3\right)}\)
\(=\frac{15\sqrt{x}-11+3x+7\sqrt{x}-6-3\sqrt{x}+3}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+3\right)}\)
\(=\frac{3x+19\sqrt{x}-14}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+3\right)}=\frac{\left(\sqrt{x}+7\right)\left(3\sqrt{x}-2\right)}{\left(\sqrt{x}-1\right)\left(\sqrt{x}+3\right)}\)
Rút gọn biểu thức sau
P=\(\dfrac{3-\sqrt{x}}{\sqrt{x}-2}+1:\left(\dfrac{\sqrt{x}}{\sqrt{x}-2}-\dfrac{\sqrt{x}+1}{\sqrt{x}+2}+\dfrac{2\sqrt{x+7}}{4-x}\right)\)
giải chi tiết hộ mình vs ạ !!!
\(P=\dfrac{3-\sqrt{x}}{\sqrt{x}-2}+1:\left(\dfrac{\sqrt{x}}{\sqrt{x}-2}-\dfrac{\sqrt{x}+1}{\sqrt{x}+2}-\dfrac{2\sqrt{x}+7}{x-4}\right)\)
\(=\dfrac{3-\sqrt{x}}{\sqrt{x}-2}+1:\left(\dfrac{x+2\sqrt{x}-x+\sqrt{x}+2-2\sqrt{x}-7}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}\right)\)
\(=\dfrac{3-\sqrt{x}}{\sqrt{x}-2}+\dfrac{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}{\sqrt{x}-5}\)
\(=\dfrac{-x+8\sqrt{x}-15+\left(x-4\right)\left(\sqrt{x}-2\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-5\right)}\)
\(=\dfrac{-x+8\sqrt{x}-15+x\sqrt{x}-2x-4\sqrt{x}+8}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-5\right)}\)
\(=\dfrac{x\sqrt{x}-3x+4\sqrt{x}-7}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-5\right)}\)
\(ĐK:x\ge0;x\ne4\\ P=\dfrac{3-\sqrt{x}}{\sqrt{x}-2}+1:\dfrac{x+2\sqrt{x}-x+\sqrt{x}+2-2\sqrt{x}-7}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}\\ P=\dfrac{3-\sqrt{x}}{\sqrt{x}-2}+\dfrac{\left(\sqrt{x}-2\right)\left(\sqrt{x}+2\right)}{\sqrt{x}-5}\\ P=\dfrac{\left(3-\sqrt{x}\right)\left(\sqrt{x}-5\right)+\left(x-4\right)\left(\sqrt{x}-2\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-5\right)}\\ P=\dfrac{8\sqrt{x}-15-x+x\sqrt{x}-2x-4\sqrt{x}+8}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-5\right)}\\ P=\dfrac{x\sqrt{x}-3x+4\sqrt{x}-7}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-5\right)}\)
\(\lim\limits_{x\to 1}\) \(\dfrac{\sqrt[3]{x+7}-\sqrt{x+3}}{x^2-3x+2}\)
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