Violympic toán 9
Các câu hỏi tương tự
\(A=\left(\frac{4\sqrt{y}\left(2-\sqrt{y}\right)+8y}{\left(2+\sqrt{y}\right)\left(2-\sqrt{y}\right)}\right):\left(\frac{\sqrt{y}-1}{y-2\sqrt{y}}-\frac{2}{\sqrt{y}}\right)\)
a) rút gọn
b) tìm y để A = -2
giúp mk vs ạ, mik c.ơn
Giải hệ phương trình :
\(\left\{{}\begin{matrix}\sqrt{5}x-y=\sqrt{5}\left(\sqrt{3}-1\right)\\2\sqrt{3}+3\sqrt{5}=21\end{matrix}\right.\)
Bạn nào nhanh giúp mik , mik sẽ tick
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!!
29 tháng 12 2020 lúc 20:46
Cho
\(\sqrt{a}+\sqrt{b}+\sqrt{c}=\sqrt{3}\)
\(\sqrt{\left(a+2b\right)\left(a+2c\right)}+\sqrt{\left(b+2a\right)\left(b+2c\right)}+\sqrt{\left(c+2a\right)\left(c+2b\right)}=3\)
Hãy tính \(\left(2\sqrt{a}+3\sqrt{b}-4\sqrt{c}\right)^2\)
Tính:
\(a)D=\left(\sqrt{2}-\sqrt{3-\sqrt{5}}\right)\left(-\sqrt{2}\right)\\ b)2\sqrt{3}\left(\sqrt{27}+2\sqrt{48}\right)-\sqrt{75}\\ c)E=\left(\sqrt{10}+\sqrt{6}\right)\sqrt{8-2\sqrt{15}}\\ d)P=\sqrt{2+\sqrt{3}}+\sqrt{2-\sqrt{3}}\)
\(e)M=-3\sqrt{50}+2\sqrt{98}-7\sqrt{72}\)
Tính B = \(5\left(\sqrt{2+\sqrt{3}+}\sqrt{3-\sqrt{5}-\sqrt{\dfrac{5}{2}}}\right)^2+\left(\sqrt{2-\sqrt{3}}+\sqrt{3+\sqrt{5}}-\sqrt{\dfrac{3}{2}}\right)^2\)
Các bạn giúp mình với nha :)) cảm ơn các bạn nhiều ạ <3
18 tháng 6 2021 lúc 22:43
\(\sqrt[3]{\left(x+1\right)^2}+\sqrt[3]{\left(x-1\right)^2}+\sqrt[3]{x^2-1}=1\)
Dùng pp đặt ẩn phụ ạ. Em cảm ơn ạ.
Tính:a. Asqrt{12}-2sqrt{48}+dfrac{7}{5}sqrt{75}b. Bsqrt{14-6sqrt{5}}+sqrt{left(2-sqrt{5}right)^2}c. Cleft(sqrt{6}-sqrt{2}right)sqrt{2+sqrt{3}}d. Ddfrac{5+sqrt{5}}{sqrt{5}+2}+dfrac{sqrt{5}-5}{sqrt{5}}-dfrac{11}{2sqrt{5}+3}
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Tính:
\(a.\) \(A=\sqrt{12}-2\sqrt{48}+\dfrac{7}{5}\sqrt{75}\)
\(b.\) \(B=\sqrt{14-6\sqrt{5}}+\sqrt{\left(2-\sqrt{5}\right)^2}\)
\(c.\) \(C=\left(\sqrt{6}-\sqrt{2}\right)\sqrt{2+\sqrt{3}}\)
\(d.\) \(D=\dfrac{5+\sqrt{5}}{\sqrt{5}+2}+\dfrac{\sqrt{5}-5}{\sqrt{5}}-\dfrac{11}{2\sqrt{5}+3}\)
Bài 1: Rút gọn biểu thức
a) Asqrt{26+15sqrt{3}}
b) Bsqrt{4+sqrt{7}}-sqrt{4-sqrt{7}}-sqrt{2}
c) Csqrt{8-2sqrt{15}}-sqrt{8+2sqrt{15}}
d) Dleft(sqrt{6}-2right)left(5+sqrt{24}right)sqrt{5-sqrt{24}}
e) Eleft(sqrt{10}-sqrt{2}right)left(sqrt{3+sqrt{5}}right)
f) Fsqrt{sqrt{5}-sqrt{3-sqrt{29-12sqrt{5}}}}
g) Gleft(2-sqrt{3}right)sqrt{26+15sqrt{3}}-left(2+sqrt{3}right)sqrt{26-15sqrt{3}}
h) Hfrac{left(2+sqrt{3}right)sqrt{2-sqrt{3}}}{sqrt{2+sqrt{3}}}
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Bài 1: Rút gọn biểu thức
a) \(A=\sqrt{26+15\sqrt{3}}\)
b) \(B=\sqrt{4+\sqrt{7}}-\sqrt{4-\sqrt{7}}-\sqrt{2}\)
c) \(C=\sqrt{8-2\sqrt{15}}-\sqrt{8+2\sqrt{15}}\)
d) \(D=\left(\sqrt{6}-2\right)\left(5+\sqrt{24}\right)\sqrt{5-\sqrt{24}}\)
e) \(E=\left(\sqrt{10}-\sqrt{2}\right)\left(\sqrt{3+\sqrt{5}}\right)\)
f) \(F=\sqrt{\sqrt{5}-\sqrt{3-\sqrt{29-12\sqrt{5}}}}\)
g) \(G=\left(2-\sqrt{3}\right)\sqrt{26+15\sqrt{3}}-\left(2+\sqrt{3}\right)\sqrt{26-15\sqrt{3}}\)
h) \(H=\frac{\left(2+\sqrt{3}\right)\sqrt{2-\sqrt{3}}}{\sqrt{2+\sqrt{3}}}\)