\(\frac{\sqrt{44-15\sqrt{7}}+\sqrt{32-3\sqrt{7}}}{\sqrt{12-3\sqrt{7}}}-\sqrt{21-12\sqrt{3}}\) rút gọn biểu thức
Rút gọn biểu thức sau:
A= \(\sqrt{11-4\sqrt{7}}+\frac{4}{3-\sqrt{7}}-\frac{21}{\sqrt{7}}\)
A=\(\sqrt{\left(\sqrt{7}-2\right)^2}\)+\(\frac{25\sqrt{7}-63}{3\sqrt{7}-7}\)=\(\frac{12\sqrt{7}-28}{3\sqrt{7}-7}\)=4
Rút gọn biểu thức
\(P=\frac{\sqrt{\sqrt{7}-\sqrt{3}}-\sqrt{\sqrt{7}+\sqrt{3}}}{\sqrt{\sqrt{7}-2}}\)
Rút gọn biểu thức :
\(\frac{(\sqrt{x}-3)^2+12\sqrt{x}}{3+\sqrt{x}}\)
\(\frac{\left(\sqrt{x}-3\right)^2+12\sqrt{x}}{3+\sqrt{x}}=\) \(\frac{x-6\sqrt{x}+9+12\sqrt{x}}{3+\sqrt{x}}\)
\(=\frac{x+6\sqrt{x}+9}{3+\sqrt{x}}\)
\(=\frac{\left(3+\sqrt{x}\right)^2}{3+\sqrt{x}}\)
\(=3+\sqrt{x}\)
\(\frac{\left(\sqrt{x}-3\right)^2+12\sqrt{x}}{3+\sqrt{x}}\left(x\ge0\right)=\frac{x-6\sqrt{x}+9+12\sqrt{x}}{3+\sqrt{x}}\)
\(=\frac{x+\sqrt{6}+9}{3+\sqrt{x}}=\frac{\left(\sqrt{x}+3\right)^2}{3+\sqrt{x}}=3+\sqrt{x}\left(x\ge0\right)\)
Rút gọn các biểu thức sau
a \(\left(2\sqrt{3}+\sqrt{5}\right)\sqrt{3}-\sqrt{60}\)
b \(\left(5\sqrt{2}+2\sqrt{5}\right)\sqrt{5}-\sqrt{250}\)
c\(\left(\sqrt{28}-\sqrt{12}-\sqrt{7}\right)\sqrt{7}+2\sqrt{21}\)
d \(\left(\sqrt{99}-\sqrt{18}-\sqrt{11}\right)\sqrt{11}+3\sqrt{22}\)
Rút gọn biểu thức : A=\(\frac{3}{\sqrt{7}+2}\)+\(\frac{4}{3-\sqrt{7}}\)-\(\frac{21}{\sqrt{7}}\)
Lời giải:
\(A=\frac{3}{\sqrt{7}+2}+\frac{4}{3-\sqrt{7}}-\frac{21}{\sqrt{7}}=\frac{3(\sqrt{7}-2)}{(\sqrt{7}+2)(\sqrt{7}-2)}+\frac{4(3+\sqrt{7})}{(3-\sqrt{7})(3+\sqrt{7})}-\frac{21\sqrt{7}}{7}\)
\(=\frac{3(\sqrt{7}-2)}{7-2^2}+\frac{4(3+\sqrt{7})}{3^2-7}-3\sqrt{7}\)
\(=\sqrt{7}-2+2(3+\sqrt{7})-3\sqrt{7}=4\)
A=\(\sqrt{45a}-2\sqrt{\frac{4a}{3}}+\frac{\sqrt{18a}}{\sqrt{6}}+\sqrt{5\frac{1}{3}a}\)
Rút gọn biểu thức A
Rút gọn biểu thức: \(\frac{\sqrt{3-2\sqrt{2}}}{\sqrt{17-12\sqrt{2}}}-\frac{\sqrt{3+2\sqrt{2}}}{\sqrt{17+12\sqrt{2}}}\)
CÁC BN GIÚP MK VS,,,
Rút gọn biểu thức sau
\(A=\frac{\sqrt{x+2}}{\sqrt{x-3}}-\frac{\sqrt{x+1}}{\sqrt{x-2}}-\frac{3\sqrt{x-3}}{x-5\sqrt{x+6}}\)
Rút gọn biểu thức sau :
A=\(\dfrac{3}{2\sqrt{3}}+\dfrac{3-\sqrt{3}}{1-\sqrt{3}}\)