Violympic toán 9
Các câu hỏi tương tự
giải hệ
\(\left\{{}\begin{matrix}\dfrac{\left(x-y\right)^2-1}{xy}-\dfrac{2\left(x+y-1\right)}{x+y}=-4\\4x^2+5y+\sqrt{x+y-1}+6\sqrt{x}=13\end{matrix}\right.\)
Tim x, y, z
1/ sqrt{x-2}+sqrt{y-2008}+sqrt{z-2009}dfrac{1}{2}left(x+y+zright)
2/ x+y+z+42sqrt{x-2}+4sqrt{y-3}+6sqrt{x-5}
3/ Tinh T x^2+y^2+z^2-7 biet x-y-z 2sqrt{x-34}+4sqrt{y-21}+6sqrt{z-4}+45
4/ 2x^2+9y^2-6xy-12y-6x+290
5/4x^2+3y-4x+4xy-10y+90
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Tim x, y, z
1/ \(\sqrt{x-2}+\sqrt{y-2008}+\sqrt{z-2009}=\dfrac{1}{2}\left(x+y+z\right)\)
2/ \(x+y+z+4=2\sqrt{x-2}+4\sqrt{y-3}+6\sqrt{x-5}\)
3/ Tinh T = \(x^2+y^2+z^2-7\) biet x-y-z = \(2\sqrt{x-34}+4\sqrt{y-21}+6\sqrt{z-4}+45\)
4/ \(2x^2+9y^2-6xy-12y-6x+29=0\)
5/\(4x^2+3y-4x+4xy-10y+9=0\)
Giải hệ pt
1/left{{}begin{matrix}4xsqrt{y+1}+8xleft(4x^2-4x-3right)sqrt{x+1}dfrac{x}{x+1}+x^2left(y+2right)sqrt{left(x+1right)left(y+1right)}end{matrix}right.
2/left{{}begin{matrix}xsqrt{y^2+6}+ysqrt{x^2+3}7xyxsqrt{x^2+3}+ysqrt{y^2+6}x^2+y^2+2end{matrix}right.left{{}begin{matrix}xsqrt{y^2+6}+ysqrt{x^2+3}7xyxsqrt{x^2+3}+ysqrt{y^2+6}x^2+y^2+2end{matrix}right.
3/left{{}begin{matrix}left(2x+y-1right)left(sqrt{x+3}+sqrt{xy}+sqrt{x}right)8sqrt{x}left(sqrt{x+3}+sqrt{xy}right)^2+xy2xleft(6-xright)end...
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Giải hệ pt
1/\(\left\{{}\begin{matrix}4x\sqrt{y+1}+8x=\left(4x^2-4x-3\right)\sqrt{x+1}\\\dfrac{x}{x+1}+x^2=\left(y+2\right)\sqrt{\left(x+1\right)\left(y+1\right)}\end{matrix}\right.\)
2/\(\left\{{}\begin{matrix}x\sqrt{y^2+6}+y\sqrt{x^2+3}=7xy\\x\sqrt{x^2+3}+y\sqrt{y^2+6}=x^2+y^2+2\end{matrix}\right.\)\(\left\{{}\begin{matrix}x\sqrt{y^2+6}+y\sqrt{x^2+3}=7xy\\x\sqrt{x^2+3}+y\sqrt{y^2+6}=x^2+y^2+2\end{matrix}\right.\)
3/\(\left\{{}\begin{matrix}\left(2x+y-1\right)\left(\sqrt{x+3}+\sqrt{xy}+\sqrt{x}\right)=8\sqrt{x}\\\left(\sqrt{x+3}+\sqrt{xy}\right)^2+xy=2x\left(6-x\right)\end{matrix}\right.\)\(\left\{{}\begin{matrix}\left(2x+y-1\right)\left(\sqrt{x+3}+\sqrt{xy}+\sqrt{x}\right)=8\sqrt{x}\\\left(\sqrt{x+3}+\sqrt{xy}\right)^2+xy=2x\left(6-x\right)\end{matrix}\right.\)
4/\(\left\{{}\begin{matrix}\sqrt{xy+x+2}+\sqrt{x^2+x}-4\sqrt{x}=0\\xy+x^2+2=x\left(\sqrt{xy+2}+3\right)\end{matrix}\right.\)\(\left\{{}\begin{matrix}\sqrt{xy+x+2}+\sqrt{x^2+x}-4\sqrt{x}=0\\xy+x^2+2=x\left(\sqrt{xy+2}+3\right)\end{matrix}\right.\)
m.n giúp e mấy bài này vs ạ!!
Giải hệ phương trình:
1. left{{}begin{matrix}x+32sqrt{left(3y-xright)left(y+1right)}sqrt{3y-2}-sqrt{dfrac{x+5}{2}}xy-2y-2end{matrix}right.
2. left{{}begin{matrix}sqrt{2y^2-7y+10-xleft(y+3right)}+sqrt{y+1}x+1sqrt{y+1}+dfrac{3}{x+1}x+2yend{matrix}right.
3. left{{}begin{matrix}sqrt{4x-y}-sqrt{3y-4x}12sqrt{3y-4x}+yleft(5x-yright)xleft(4x+yright)-1end{matrix}right.
4. left{{}begin{matrix}9sqrt{dfrac{41}{2}left(x^2+dfrac{1}{2x+y}right)}3+40xx^2+5xy+6y4y^2+9x+9end{matrix}right.
5. left{{}begin{mat...
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Giải hệ phương trình:
1. \(\left\{{}\begin{matrix}x+3=2\sqrt{\left(3y-x\right)\left(y+1\right)}\\\sqrt{3y-2}-\sqrt{\dfrac{x+5}{2}}=xy-2y-2\end{matrix}\right.\)
2. \(\left\{{}\begin{matrix}\sqrt{2y^2-7y+10-x\left(y+3\right)}+\sqrt{y+1}=x+1\\\sqrt{y+1}+\dfrac{3}{x+1}=x+2y\end{matrix}\right.\)
3. \(\left\{{}\begin{matrix}\sqrt{4x-y}-\sqrt{3y-4x}=1\\2\sqrt{3y-4x}+y\left(5x-y\right)=x\left(4x+y\right)-1\end{matrix}\right.\)
4. \(\left\{{}\begin{matrix}9\sqrt{\dfrac{41}{2}\left(x^2+\dfrac{1}{2x+y}\right)}=3+40x\\x^2+5xy+6y=4y^2+9x+9\end{matrix}\right.\)
5. \(\left\{{}\begin{matrix}\sqrt{xy+\left(x-y\right)\left(\sqrt{xy}-2\right)}+\sqrt{x}=y+\sqrt{y}\\\left(x+1\right)\left[y+\sqrt{xy}+x\left(1-x\right)\right]=4\end{matrix}\right.\)
6. \(\left\{{}\begin{matrix}x^4-x^3+3x^2-4y-1=0\\\sqrt{\dfrac{x^2+4y^2}{2}}+\sqrt{\dfrac{x^2+2xy+4y^2}{3}}=x+2y\end{matrix}\right.\)
7. \(\left\{{}\begin{matrix}x^3-12z^2+48z-64=0\\y^3-12x^2+48x-64=0\\z^3-12y^2+48y-64=0\end{matrix}\right.\)
NC
19 tháng 9 2019 lúc 20:59
Bài 1: Tìm x
a, sqrt{4x+1} 4
b, sqrt{3-x} 2
c, sqrt{x+1} + frac{1}{2}sqrt{4x+4} 6 - frac{1}{3}sqrt{9x+9}
d, sqrt{4x^2-12x+9} - x 5
e, sqrt{16x^2+8x+1} 10
Bài 2: Tìm x,y,z
x + y + z 2sqrt{x}+ 2sqrt{y-3} + 2sqrt{z}
Bài 3: Cho x y 0
Rút gọn sqrt{x^2}+sqrt{y^2}-sqrt{x^2-2xy+y^2}
Bài 4: Tìm GTNN
a, x - 2sqrt{x} + 3
b, sqrt{x-4sqrt{y}+13}
c, sqrt{2x-4sqrt{y}+6}
d, -frac{4}{x^2+2x+5}
Bài 5: Cho A frac{3sqrt{x}+11}{sqrt{x}+2}
Tìm x ϵ Z để A nguyên
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Bài 1: Tìm x
a, \(\sqrt{4x+1}\) = 4
b, \(\sqrt{3-x}\) = 2
c, \(\sqrt{x+1}\) + \(\frac{1}{2}\sqrt{4x+4}\) = 6 - \(\frac{1}{3}\sqrt{9x+9}\)
d, \(\sqrt{4x^2-12x+9}\) - x = 5
e, \(\sqrt{16x^2+8x+1}\) = 10
Bài 2: Tìm x,y,z
x + y + z = 2\(\sqrt{x}\)+ 2\(\sqrt{y-3}\) + 2\(\sqrt{z}\)
Bài 3: Cho x < y < 0
Rút gọn \(\sqrt{x^2}+\sqrt{y^2}-\sqrt{x^2-2xy+y^2}\)
Bài 4: Tìm GTNN
a, x - 2\(\sqrt{x}\) + 3
b, \(\sqrt{x-4\sqrt{y}+13}\)
c, \(\sqrt{2x-4\sqrt{y}+6}\)
d, \(-\frac{4}{x^2+2x+5}\)
Bài 5: Cho A = \(\frac{3\sqrt{x}+11}{\sqrt{x}+2}\)
Tìm x ϵ Z để A nguyên
Cho x,y thỏa mãn x>1, y<0 và \(\frac{\left(x+y\right)\left(x^3-y^3\right)\sqrt{4x-2\sqrt{4x-1}}}{\left(1-\sqrt{4x-1}\right)\left(x^2y^2+xy^3+y^4\right)}=-8\). Vậy \(\frac{x}{y}=\)
Bài 1 : Tìm GTNN của biểu thức : \(A=\sqrt{5x^2+10x+9}+\sqrt{2x^2+4x+3}\)
Bài 2 : Tìm x biết :
a, \(\sqrt{x}< \sqrt{x+1}\)
b, \(\sqrt{x-1}>4\)
c, \(\sqrt{4x^2+4x+1}+\sqrt{2x-1}=0\)
Bài 3 Tìm x,y thuộc Z
a, \(x^2+4x-y=1\)
b, \(x^2-3xy+2y^2+6=0\)
Cho các số x,y,z >0 thỏa mãn x+y+z = 12. Tìm GTLN của biểu thức: \(A=\sqrt{4x+2\sqrt{x}+1}+\sqrt{4y+2\sqrt{y}+1}+\sqrt{4z+2\sqrt{z}+1}\)
a, Giải phương trình : \(2\sqrt[3]{6-4x}+3\sqrt{3-2x}=10\)
b, giải hệ : \(\left\{{}\begin{matrix}2x^2-xy-y^2+2x+y=0\\\sqrt{x+y}+\sqrt{3x+y}=2\end{matrix}\right.\)