6) (3\(\sqrt{2}\) -\(\sqrt{3}\))(\(\sqrt{3}\)+3\(\sqrt{2}\))
7) \(\sqrt{72}\)+\(\sqrt{4\dfrac{1}{2}}\) - \(\sqrt{32}\) - \(\sqrt{162}\)
tính
A=\(\left(1-\sqrt{7}\right).\dfrac{\sqrt{7}+7}{2\sqrt{7}}\)
B=\(3\sqrt{3}+4\sqrt{12}-5\sqrt{27}\)
C=\(\sqrt{32}-\sqrt{50}+\sqrt{18}\)
D=\(\sqrt{72}+\sqrt{4\dfrac{1}{2}}-\sqrt{32}-\sqrt{162}\)
E=\(\dfrac{1}{2}\sqrt{48}-2\sqrt{75}-\dfrac{\sqrt{33}}{\sqrt{11}}+5\sqrt{1\dfrac{1}{3}}\)
a: \(A=\left(1-\sqrt{7}\right)\cdot\left(1+\sqrt{7}\right)=1-7=-6\)
b: \(B=3\sqrt{3}+8\sqrt{3}-15\sqrt{3}=-4\sqrt{3}\)
c: \(C=4\sqrt{2}-5\sqrt{2}+3\sqrt{2}=2\sqrt{2}\)
chỉ cần đưa về dạng hằng đảng thức thôi , xin cam ơn mọi người
1,\(\sqrt{26+15\sqrt{3}}\)
2,\(\sqrt{8-2\sqrt{15}}-\sqrt{23-4\sqrt{5}}\)
3,\(\sqrt{12-3\sqrt{7}}-\sqrt{12-3\sqrt{7}}\)
4,\(\sqrt{7-2\sqrt{10}}-\sqrt{7+2\sqrt{10}}\)
5,\(\sqrt{4+\sqrt{10+2\sqrt{5}}}+\sqrt{4-\sqrt{10+2\sqrt{5}}}\)
6,\(3\sqrt{3}+4\sqrt{12}-5\sqrt{27}\)
7,\(\sqrt{32}-\sqrt{50}+\sqrt{18}\)
8,\(\sqrt{72}+\sqrt{4\dfrac{1}{2}}-\sqrt{32}-\sqrt{162}\)
9,\(\dfrac{1}{2}\sqrt{48}-2\sqrt{75}-\dfrac{\sqrt{33}}{\sqrt{11}}+5\sqrt{1\dfrac{1}{3}}\)
3: \(\sqrt{12-3\sqrt{7}}-\sqrt{12-3\sqrt{7}}=0\)
4: \(\sqrt{7-2\sqrt{10}}-\sqrt{7+2\sqrt{10}}\)
\(=\sqrt{5}-\sqrt{2}-\sqrt{5}-\sqrt{2}\)
\(=-2\sqrt{2}\)
6: \(3\sqrt{3}+4\sqrt{12}-5\sqrt{27}\)
\(=3\sqrt{3}+8\sqrt{3}-15\sqrt{3}\)
\(=-4\sqrt{3}\)
2 . rút gọn biểu thức
a. \(\sqrt{200}-\sqrt{32}+\sqrt{72}\)
b. \(\sqrt{175}-\sqrt{112}+\sqrt{63}\)
c. \(\dfrac{3}{2}\sqrt{6}+2\sqrt{\dfrac{2}{3}}-4\sqrt{\dfrac{3}{2}}\)
d. \(4\sqrt{20}-3\sqrt{125}+5\sqrt{45}-15\sqrt{\dfrac{1}{5}}\)
e. \(5\sqrt{\dfrac{1}{5}+}\dfrac{1}{5}\sqrt{20}+\sqrt{5}\)
f. \(\sqrt{\dfrac{1}{5}}+\sqrt{4,5}+\sqrt{12,5}\)
g. \(\dfrac{1}{2}\sqrt{48}-2\sqrt{75}-\sqrt{54}+5\sqrt{1\dfrac{1}{3}}\)
m. \(3\sqrt{5a}-\sqrt{20a}+\sqrt{a}+4\sqrt{45a}\)
n. \(3\sqrt{8}-\sqrt{18}-5\sqrt{\dfrac{1}{2}}+\sqrt{50}\)
i. \(\sqrt{72}+\sqrt{4\dfrac{1}{2}}-\sqrt{32}+\sqrt{63}-\sqrt{162}\)
a: \(=10\sqrt{2}-4\sqrt{2}+6\sqrt{2}=12\sqrt{2}\)
b: \(=5\sqrt{7}-4\sqrt{7}+3\sqrt{7}=4\sqrt{7}\)
c: \(=\dfrac{3}{2}\sqrt{6}+\dfrac{2}{3}\sqrt{6}-2\sqrt{6}=\dfrac{1}{6}\sqrt{6}\)
d: \(=8\sqrt{5}-15\sqrt{5}+15\sqrt{5}-3\sqrt{5}=5\sqrt{5}\)
e: \(=\sqrt{5}+\dfrac{2}{5}\sqrt{5}+\sqrt{5}=2.4\sqrt{5}\)
f: \(=\dfrac{1}{5}\sqrt{5}+\dfrac{3}{2}\sqrt{2}+\dfrac{5}{2}\sqrt{2}=\dfrac{1}{5}\sqrt{5}+4\sqrt{2}\)
a, \(\sqrt{200}-\sqrt{32}+\sqrt{72}\)
b, \(4\sqrt{20}-3\sqrt{125}+5\sqrt{45}-15\sqrt{\dfrac{1}{5}}\)
c, \(\left(2\sqrt{8}+3\sqrt{5}-7\sqrt{2}\right)\left(72-5\sqrt{20}-2\sqrt{2}\right)\)
a) \(\sqrt{200}-\sqrt{32}+\sqrt{72}\)
\(=\sqrt{10^2\cdot2}-\sqrt{4^2\cdot2}+\sqrt{6^2\cdot2}\)
\(=10\sqrt{2}-4\sqrt{2}+6\sqrt{2}\)
\(=\left(10-4+6\right)\sqrt{2}\)
\(=12\sqrt{2}\)
b) \(4\sqrt{20}-3\sqrt{125}+5\sqrt{45}-15\sqrt{\dfrac{1}{5}}\)
\(=4\cdot2\sqrt{5}-3\cdot5\sqrt{5}+5\cdot3\sqrt{5}-3\sqrt{5}\)
\(=8\sqrt{5}-15\sqrt{5}+15\sqrt{5}-3\sqrt{5}\)
\(=\left(8-15+15-3\right)\sqrt{5}\)
\(=5\sqrt{5}\)
c) \(\left(2\sqrt{8}+3\sqrt{5}-7\sqrt{2}\right)\left(72-5\sqrt{20}-2\sqrt{2}\right)\)
\(=\left(2\cdot2\sqrt{2}+3\sqrt{5}-7\sqrt{2}\right)\left(72-5\cdot2\sqrt{5}-2\sqrt{2}\right)\)
\(=\left(3\sqrt{5}-3\sqrt{2}\right)\left(72-10\sqrt{5}-2\sqrt{2}\right)\)
I.
1, \(\sqrt{8}-3\sqrt{32}+\sqrt{72}\)
2, \(6\sqrt{12}-2\sqrt{48}+5\sqrt{75}-7\sqrt{108}\)
3, \(\sqrt{20}+3\sqrt{45}-6\sqrt{80}-\dfrac{1}{3}\sqrt{125}\)
4, \(2\sqrt{5}-\sqrt{125}-\sqrt{80}\)
5, \(3\sqrt{2}-\sqrt{8}+\sqrt{50}-4\sqrt{32}\)
1, \(\sqrt{8}-3\sqrt{32}+\sqrt{72}=2\sqrt{2}-12\sqrt{2}+6\sqrt{2}=-4\sqrt{2}\)
2,\(6\sqrt{12}-2\sqrt{48}+5\sqrt{75}-7\sqrt{108}=12\sqrt{3}-8\sqrt{3}+25\sqrt{3}-42\sqrt{3}=-13\sqrt{3}\)
3, \(\sqrt{20}+3\sqrt{45}-6\sqrt{80}-\dfrac{1}{3}\sqrt{125}=2\sqrt{5}+9\sqrt{5}-24\sqrt{5}-\dfrac{5}{3}.\sqrt{5}=-\dfrac{44}{3}.\sqrt{5}\)
4, \(2\sqrt{5}-\sqrt{125}-\sqrt{80}=2\sqrt{5}-5\sqrt{5}-4\sqrt{5}=-7\sqrt{5}\)
5, \(3\sqrt{2}-\sqrt{8}+\sqrt{50}-4\sqrt{32}=3\sqrt{2}-2\sqrt{2}+5\sqrt{2}-16\sqrt{2}=-10\sqrt{2}\)
\(\sqrt{72}+\sqrt{4\dfrac{1}{2}-\sqrt{32}}-\sqrt{162}\)
\(-\dfrac{6\sqrt{2}-\sqrt{\left(9-8\sqrt{2}\right)\cdot2}}{2}\)
\(\sqrt{2.36}+\sqrt{2.\dfrac{9}{4}}-\sqrt{2.16}-\sqrt{2.81}=6\sqrt{2}+\dfrac{3}{2}\sqrt{2}-4\sqrt{2}-9\sqrt{2}=\dfrac{-11}{2}\sqrt{2}\)
\(\sqrt{4\dfrac{1}{2}}+\sqrt{32}-\sqrt{72}+\sqrt{162}\)
\(\sqrt{4\dfrac{1}{2}}+\sqrt{32}-\sqrt{72}+\sqrt{162}\\ =\sqrt{\dfrac{4\cdot2+1}{2}}+\sqrt{4^2\cdot2}-\sqrt{6^2\cdot2}+\sqrt{9^2\cdot2}\\ =\sqrt{\dfrac{9}{2}}+4\sqrt{2}-6\sqrt{2}+9\sqrt{2}\\ =\dfrac{3}{\sqrt{2}}+7\sqrt{2}\\ =\dfrac{3}{\sqrt{2}}+\dfrac{7\sqrt{2}\cdot\sqrt{2}}{\sqrt{2}}\\ =\dfrac{17}{\sqrt{2}}\)
\(=\sqrt{\dfrac{9}{2}}+4\sqrt{2}-6\sqrt{2}+9\sqrt{2}\)
\(=\dfrac{3}{2}\sqrt{2}+7\sqrt{2}=\dfrac{17}{2}\sqrt{2}\)
\(\sqrt{4\dfrac{1}{2}}+\sqrt{32}-\sqrt{72}+\sqrt{162}\)
\(=\sqrt{\dfrac{9}{2}}+\sqrt{4^2.2}-\sqrt{6^2.2}+\sqrt{9^2.2}\)
\(=\dfrac{3}{\sqrt{2}}+4\sqrt{2}-6\sqrt{2}+9\sqrt{2}\)
\(=\dfrac{3\sqrt{2}}{2}+7\sqrt{2}=\dfrac{3\sqrt{2}+14\sqrt{2}}{2}=\dfrac{17\sqrt{2}}{2}\)
Rút Gọn
1.\(3\sqrt{3}+4\sqrt{12}-5\sqrt{27}\)
2.\(\sqrt{32}-\sqrt{50}+\sqrt{18}\)
3.\(\sqrt{72}+\sqrt{4\frac{1}{2}}-\sqrt{32}-\sqrt{162}\)
4.\(\left(\sqrt{325}-\sqrt{117}+2\sqrt{208}\right):\sqrt{13}\)
5.\(\left(\sqrt{12}-\sqrt{48}-\sqrt{108}-\sqrt{192}\right):2\sqrt{3}\)
6.\(\left(2\sqrt{112}-5\sqrt{7}+2\sqrt{63}-2\sqrt{28}\right)\sqrt{7}\)
7.\(\left(2\sqrt{27}-3\sqrt{48}+3\sqrt{75}-\sqrt{192}\right)\left(1-\sqrt{3}\right)\)
8.\(7\sqrt{24}-\sqrt{150}-5\sqrt{54}\)
9.\(2\sqrt{20}-\sqrt{50}+3\sqrt{80}-\sqrt{320}\)
10.\(\sqrt{32}-\sqrt{50}+\sqrt{98}-\sqrt{72}\)
11.\(3\sqrt{2}-4\sqrt{18}+2\sqrt{32}-\sqrt{50}\)
12.\(5\sqrt{48}-4\sqrt{27}-2\sqrt{75}+\sqrt{108}\)
13.\(2\sqrt{24}-2\sqrt{54}+3\sqrt{6}-\sqrt{150}\)
14.\(\sqrt{125}-2\sqrt{20}-3\sqrt{80}+4\sqrt{45}\)
15.\(2\sqrt{28}+2\sqrt{63}-3\sqrt{175}+\sqrt{112}\)
16.\(10\sqrt{28}-2\sqrt{275}-3\sqrt{343}-\frac{3}{2}\sqrt{396}\)
Tính:
\(\dfrac{\sqrt[4]{7\sqrt[3]{54}+15\sqrt[3]{128}}}{\sqrt[3]{\sqrt[4]{32}}+\sqrt[3]{9\sqrt[4]{162}}}\)
\(A=\dfrac{\sqrt[4]{7\sqrt[3]{54}+15\sqrt[3]{128}}}{\sqrt[3]{\sqrt[4]{32}}+\sqrt[3]{9\sqrt[4]{162}}}\)
\(\Leftrightarrow A=\dfrac{\sqrt[4]{7\sqrt[3]{3^3.2}+15\sqrt[3]{4^3.2}}}{\sqrt[3]{\sqrt[4]{2^4.2}}+\sqrt[3]{9\sqrt[4]{3^4.2}}}\)
\(\Leftrightarrow A=\dfrac{\sqrt[4]{7.3\sqrt[3]{2}+15.4\sqrt[3]{2}}}{\sqrt[3]{2\sqrt[4]{2}}+\sqrt[3]{9.3\sqrt[4]{2}}}\)
\(\Leftrightarrow A=\dfrac{\sqrt[4]{21\sqrt[3]{2}+60\sqrt[3]{2}}}{\sqrt[3]{2\sqrt[4]{2}}+\sqrt[3]{3^3\sqrt[4]{2}}}\)
\(\Leftrightarrow A=\dfrac{\sqrt[4]{81\sqrt[3]{2}}}{\sqrt[3]{\sqrt[4]{2}}\left(\sqrt[3]{2}+3\right)}=\dfrac{3\sqrt[4]{\sqrt[3]{2}}}{\sqrt[3]{\sqrt[4]{2}}\left(\sqrt[3]{2}+3\right)}\)
\(\Leftrightarrow A=\dfrac{3}{\sqrt[3]{2}+3}\)