Tim x,y nguyen biet
\(\sqrt{x}+\sqrt{y}+2016=\sqrt{xy}\)
Giup minh voi!!!!!!!!!
\(A=\frac{\sqrt{x}+4}{\sqrt{x}+2};B=\left(\frac{\sqrt{x}}{\sqrt{x}+4}+\frac{4}{\sqrt{x}-4}\right):\frac{x+16}{\sqrt{x}+2}\)
a. rut gon B
b. Tim x nguyen de P = B(A-1) nguyen
giup minh voi a
Cho 2 số dương x,y. Chứng minh: \(\dfrac{2015}{2016}\sqrt{\dfrac{x}{y}}+\dfrac{2016}{2017}\sqrt{\dfrac{y}{x}}>1+\dfrac{\left(\sqrt{x}-\sqrt{y}\right)^2}{6\sqrt{xy}}\)
tim x sao cho \(\frac{9}{1+\sqrt{x}}\) la so nguyen
cac ban giup minh voi nhe
Tim ba so duong thoa man : \(2016\left(x-y\sqrt{2001}\right)=2015\left(y-\sqrt{2001}\right)\) va \(x^2+y^2+z^2\) la so nguyen to
\(\frac{x+\sqrt{xy}}{\sqrt{x}-\sqrt{y}}\)
cac ban chi cach triet tieu giup minh ik =')))
\(\frac{x+\sqrt{xy}}{\sqrt{x}-\sqrt{y}}=\frac{\sqrt{x}\left(\sqrt{x}+\sqrt{y}\right)}{\sqrt{x}-\sqrt{y}}.\)
\(=\frac{\sqrt{x}\left(\sqrt{x}+\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}\right)}{\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}\right)}\)
\(=\frac{\sqrt{x}\left(\sqrt{x}+\sqrt{y}\right)^2}{x-y}\)
Tìm x ; y biết: \(\hept{\begin{cases}x^{2017}+y^{2017}=1\\\sqrt[2017]{x}-\sqrt[2017]{y}=\left(\sqrt[2016]{y}-\sqrt[2016]{x}\right)\left(x+y+xy+2017\right)\end{cases}}\)
\(\hept{\begin{cases}x^{2017}+y^{2017}=1\left(1\right)\\\sqrt[2017]{x}-\sqrt[2017]{y}=\left(\sqrt[2016]{y}-\sqrt[2016]{x}\right)\left(x+y+xy+2017\right)\left(2\right)\end{cases}}\)
Điều kiện: \(x,y\ge0\)
Dễ thấy \(\hept{\begin{cases}x=0\\y=0\end{cases}}\)không phải là nghiệm của hệ
Đặt \(\hept{\begin{cases}\sqrt[2017.2016]{x}=a>0\\\sqrt[2017.2016]{y}=b>0\end{cases}}\)
\(\Rightarrow\left(2\right)\Leftrightarrow a^{2016}-b^{2016}=\left(b^{2017}-a^{2017}\right)A\left(x,y\right)\)
\(\Leftrightarrow\left(a-b\right).B\left(a,b\right)=\left(b-a\right).C\left(a,b\right).A\left(x,y\right)\)
\(\Leftrightarrow\left(a-b\right)\left(B\left(a,b\right)+C\left(a,b\right).A\left(x,y\right)\right)=0\)
Dễ thấy \(\left(B\left(a,b\right)+C\left(a,b\right).A\left(x,y\right)\right)>0\)
\(\Leftrightarrow a=b\)
\(\Rightarrow\sqrt[2016.2017]{x}=\sqrt[2016.2017]{y}\)
\(\Leftrightarrow x=y\)
Thế vô (1) ta được:
\(2x^{2017}=1\)
\(\Rightarrow x=y=\sqrt[2017]{\frac{1}{2}}\)
giải hệ phương trình :
\(\hept{\begin{cases}x^2+y^2=1\\\sqrt[2016]{x}-\sqrt[2016]{y}=\left(\sqrt[2017]{y}-\sqrt[2017]{x}\right)\left(x+y+xy+2017\right)\end{cases}}\)
1/ Tim x, y nguyen duong thoa man: \(y=\sqrt[3]{18+\sqrt{x+100}}+\sqrt[3]{18-\sqrt{x+100}}\)
Bai 1)Cho bieu thuc A=\(\frac{x+y-2\sqrt{xy}}{x-y}\)
a)Tim dieu kien de A co nghia
b)Rut gon A
c)Tinh A biet x=\(3+2\sqrt{2}\)va y=\(3-2\sqrt{2}\)
Bai 2) Cho bieu thuc B=\(\frac{x-3}{\sqrt{x-1}-\sqrt{2}}\)
a)Tim dieu kien de B co nghia
b)Rut gon B
c) Tinh B voi x=\(4\left(2-\sqrt{3}\right)\)
d)Tim x de B co gia tri nho nhat
a) A có nghĩa\(\Leftrightarrow x-y\ne0\Leftrightarrow x\ne y\)
b) \(A=\frac{x+y-2\sqrt{xy}}{x-y}=\frac{\left(\sqrt{x-\sqrt{y}}\right)^2}{\left(\sqrt{x}+\sqrt{y}\right)\left(\sqrt{x}-\sqrt{y}\right)}=\frac{\sqrt{x}-\sqrt{y}}{\sqrt{x}+\sqrt{y}}\)