a. \(\dfrac{\sqrt{12}-\sqrt{27}+\sqrt{48}}{1-\sqrt{5}+\sqrt{9-4\sqrt{5}}}=\dfrac{2\sqrt{3}-3\sqrt{3}+4\sqrt{3}}{1-\sqrt{5}+\sqrt{\left(\sqrt{5}-2\right)^2}}=\dfrac{3\sqrt{3}}{1-\sqrt{5}+\sqrt{5}-2}=-3\sqrt{3}\)
a. \(\dfrac{\sqrt{12}-\sqrt{27}+\sqrt{48}}{1-\sqrt{5}+\sqrt{9-4\sqrt{5}}}=\dfrac{2\sqrt{3}-3\sqrt{3}+4\sqrt{3}}{1-\sqrt{5}+\sqrt{\left(\sqrt{5}-2\right)^2}}=\dfrac{3\sqrt{3}}{1-\sqrt{5}+\sqrt{5}-2}=-3\sqrt{3}\)
Giải hệ phương trình
\(\left\{{}\begin{matrix}4\left(2x-y+3\right)-3\left(x-2y+3\right)=48\\3\left(3x-4y+3\right)+4\left(4x-2y-9\right)=48\end{matrix}\right.\)
\(\left\{{}\begin{matrix}6\left(x+y\right)=8+2x-3y\\5\left(y-x\right)=5+3x+2y\end{matrix}\right.\)
\(\left\{{}\begin{matrix}-2\left(2x+1\right)+1,5=3\left(y-2\right)-6x\\11,5-4\left(3-x\right)=2y-\left(5-x\right)\end{matrix}\right.\)
\(\left\{{}\begin{matrix}\dfrac{8x-5y-3}{7}+\dfrac{11y-4x-7}{5}=12\\\dfrac{9x+4y-13}{5}-\dfrac{3\left(x-2\right)}{4}=15\end{matrix}\right.\)
\(\left\{{}\begin{matrix}2\sqrt{3}x-\sqrt{5}y=2\sqrt{6}-\sqrt{15}\\3x-y=3\sqrt{2}-\sqrt{3}\end{matrix}\right.\)
Giải hệ phương trình sau bằng phương pháp thế
a)
\(\left\{{}\begin{matrix}\sqrt{5}+2)x+y=3-\sqrt{5}\\-x+2y=6-2\sqrt{5}\end{matrix}\right.\)
b)
\(\left\{{}\begin{matrix}5\left(x+2y\right)=3x-1\\2x+4=3\left(x-5y\right)-12\end{matrix}\right.\)
Giải hệ phương trình sau:
a. \(\left\{{}\begin{matrix}\dfrac{5}{\sqrt{x-2}}+\sqrt{3-y}=8\\\dfrac{2}{\sqrt{x-2}}+3\sqrt{3-y}=11\end{matrix}\right.\)
b. \(\left\{{}\begin{matrix}\dfrac{5}{\sqrt{x}-2}+\sqrt{3-y}=8\\\dfrac{2}{\sqrt{x}-2}+3\sqrt{3-y}=11\end{matrix}\right.\)
c. \(\left\{{}\begin{matrix}3\sqrt{2x-1}+\dfrac{4}{2-\sqrt{y}}=10\\5\sqrt{2x-1}-\dfrac{8}{2-\sqrt{y}}=2\end{matrix}\right.\)
Giải hệ pt:
a)\(\left\{{}\begin{matrix}x-\left(1+\sqrt{3}\right)y=1\\\left(1-\sqrt{3}\right)x+y=1\end{matrix}\right.\)
b)\(\left\{{}\begin{matrix}-x-\sqrt{2}y=\sqrt{3}\\\sqrt{2}x+2y=-\sqrt{6}\end{matrix}\right.\)
Giải các hệ phương trình sau bằng phương pháp thế :
a) \(\left\{{}\begin{matrix}4x+5y=3\\x-3y=5\end{matrix}\right.\);
b) \(\left\{{}\begin{matrix}7x-2y=1\\3x+y=6\end{matrix}\right.\);
c) \(\left\{{}\begin{matrix}1,3x+4,2y=12\\0,5x+2,5y=5,5\end{matrix}\right.\);
d) \(\left\{{}\begin{matrix}\sqrt{5}x-y=\sqrt{5}\left(\sqrt{3}-1\right)\\2\sqrt{3}x+3\sqrt{5}y=21\end{matrix}\right.\).
Giải hệ phương trình: \(\left\{{}\begin{matrix}\dfrac{1}{x}-\sqrt{y-1}=4\\\dfrac{2}{x}-\sqrt{y-1}=2\end{matrix}\right.\)
Giải các hệ phương trình sau bằng phương pháp thế:
a) \(\left\{{}\begin{matrix}x\sqrt{2}-y\sqrt{3}=1\\x+y\sqrt{3}=\sqrt{2}\end{matrix}\right.; \)
b) \(\left\{{}\begin{matrix}x-2\sqrt{2}y=\sqrt{5}\\x\sqrt{2}+y=1-\sqrt{10}\end{matrix}\right.; \)
c) \(\left\{{}\begin{matrix}(\sqrt{2}-1)x-y=\sqrt{2}\\x+(\sqrt{2}+1)y=1\end{matrix}\right.. \)
giải hệ phương trình \(\left\{{}\begin{matrix}x+\sqrt{5}y=\sqrt{5}\\\sqrt{3}x-y=\sqrt{3}\end{matrix}\right.\)
Giải các hệ phương trình sau bằng phương pháp thế:
a) \(\left\{{}\begin{matrix}x+y\sqrt{5}=0\\x\sqrt{5}+3y=1-\sqrt{5}\end{matrix}\right.;\)
b) \(\left\{{}\begin{matrix}\left(2-\sqrt{3}\right)x-3y=2+5\sqrt{3}\\4x+y=4-2\sqrt{3}\end{matrix}\right..\)