thực hiện phép tính
\(\sqrt{14-8\sqrt{3}}-\sqrt{24-12\sqrt{3}}\)
thực hiện phép tính \(\sqrt{14-8\sqrt{3}}-\sqrt{24-12\sqrt{3}}\)
Bài làm:
\(\sqrt{14-8\sqrt{3}}-\sqrt{24-12\sqrt{3}}\)
\(=\sqrt{8-8\sqrt{3}+6}-\sqrt{18-12\sqrt{3}+6}\)
\(=\sqrt{\left(2\sqrt{2}-\sqrt{6}\right)^2}-\sqrt{\left(3\sqrt{2}-\sqrt{6}\right)^2}\)
\(=2\sqrt{2}-\sqrt{6}-3\sqrt{2}+\sqrt{6}\)
\(=-\sqrt{2}\)
Học tốt
\(\sqrt{3.2-8\sqrt{3}+4.2}=\sqrt{\left(\sqrt{3}.\sqrt{2}\right)^2-2.2.\sqrt{2}.\sqrt{2}.\sqrt{3}+\left(2\sqrt{2}\right)^2}\)
\(=\sqrt{\left(2\sqrt{2}-\sqrt{6}\right)^2}-\sqrt{3^2.2-12\sqrt{3}+3.2}=2\sqrt{2}-\sqrt{6}-3\sqrt{2}+\sqrt{6}=-\sqrt{2}\)
Bài 1. (2,0 điểm) Thực hiện phép tính: n) 7/9 * sqrt(81) - 1/2 * sqrt(16) . c) (sqrt(8/3) - sqrt(24) + sqrt(50/3)) , sqrt 12 . » sqrt((sqrt(7) - 4) ^ 2) + sqrt(7) 1/(5 + 2sqrt(3)) + 1/(5 - 2sqrt(3))
Bài 3: Thực hiện các phép tính sau:
a) \(\sqrt{24+8\sqrt{5}}+\sqrt{9-4\sqrt{5}}\)
b) \(\sqrt{17-12\sqrt{2}}+\sqrt{9+4\sqrt{2}}\)
c) \(\sqrt{6-4\sqrt{2}}+\)\(\sqrt{22-12\sqrt{2}}\)
hộ mk với
a) \(\sqrt{24+8\sqrt{5}}+\sqrt{9-4\sqrt{5}}\)
\(=2\sqrt{5}+2+\sqrt{5}-2\)
\(=3\sqrt{5}\)
b) \(\sqrt{17-12\sqrt{2}}+\sqrt{9+4\sqrt{2}}\)
\(=3-2\sqrt{2}+2\sqrt{2}-1\)
=2
c) \(\sqrt{6-4\sqrt{2}}+\sqrt{22-12\sqrt{2}}\)
\(=2-\sqrt{2}+3\sqrt{2}-2\)
\(=2\sqrt{2}\)
thực hiện phép tính \(\sqrt{14-8\sqrt{3}}-\sqrt{24-12\sqrt{3}}\)
\(\sqrt{14-8\sqrt{3}}-\sqrt{24-12\sqrt{3}}=\dfrac{\sqrt{16-2.4.2\sqrt{3}+12}-\sqrt{36-2.6.2\sqrt{3}+12}}{\sqrt{2}}=\dfrac{\sqrt{\left(4-2\sqrt{3}\right)^2}-\sqrt{\left(6-2\sqrt{3}\right)^2}}{\sqrt{2}}=\dfrac{4-2\sqrt{3}-6+2\sqrt{3}}{\sqrt{2}}=\dfrac{-2}{\sqrt{2}}=-\sqrt{2}\)
Thực hiện phép tính (rút gọn biểu thức)
a)\(\sqrt{20}\)-3\(\sqrt{45}\)-\(\dfrac{1}{2}\sqrt{80}\)
b) 12\(\sqrt{54}\)-\(\dfrac{2}{5}\)\(\sqrt{150}\)+3\(\sqrt{24}\)
Lời giải:
a.
$=2\sqrt{5}-9\sqrt{5}-2\sqrt{5}=(2-9-2)\sqrt{5}=-9\sqrt{5}$
b.
$=36\sqrt{6}-2\sqrt{6}+6\sqrt{6}=(36-2+6)\sqrt{6}=40\sqrt{6}$
thực hiện phép tính
a)\(3\sqrt{9-\sqrt{25}+2\sqrt{49}}\)
b)\(7\sqrt[3]{27}-\sqrt[3]{64}+2\sqrt[3]{8}\)
c)\(\left(\sqrt{28}+2\sqrt{14}+3\sqrt{7}\right)\left(\sqrt{7}-7\sqrt{8}\right)\)
d)\(\frac{6\sqrt{7}+\sqrt{12}}{2}+\sqrt{7}+\sqrt{67-12\sqrt{7}}\)
Thực hiện phép tính:
a)\(\sqrt{4-2\sqrt{3}}+\sqrt{4+2\sqrt{3}}\)
b)\(\sqrt{24+8\sqrt{5}}+\sqrt{9-4\sqrt{5}}\)
c)\(\sqrt{17-12\sqrt{2}}+\sqrt{9+4\sqrt{2}}\)
d)\(\sqrt{6-4\sqrt{2}}+\sqrt{22-12\sqrt{2}}\)
a,\(\sqrt{\left(\sqrt{3}-1\right)^2}\) \(+\sqrt{\left(\sqrt{3}+1\right)^2}=2\sqrt{3}\)
b. \(\sqrt{\left(2\sqrt{5}+2\right)^2}+\sqrt{\left(\sqrt{5}-2\right)^2}=3\sqrt{5}\)
c,\(\sqrt{\left(3-2\sqrt{2}\right)^2}+\sqrt{\left(2\sqrt{2}+1\right)^2}=4\)
d.\(\sqrt{\left(2-\sqrt{2}\right)^2}+\sqrt{\left(3\sqrt{2}-2\right)^2}=2\sqrt{2}\)
\(\sqrt{8\sqrt{3}}-2\sqrt{25\sqrt{12}}+4\sqrt{\sqrt{192}}\)
Thực hiện phép tính
\(\sqrt{8\sqrt{3}}-2\sqrt{25\sqrt{12}}+4\sqrt{\sqrt{192}}=0\)
thực hiện phép tính ngắn gọn nhất
a) (\(\sqrt{12}\) +\(\sqrt{27}\) -\(\sqrt{3}\)) . \(\sqrt{3}\)
\(=\sqrt{3}\left(2\sqrt{3}+3\sqrt{3}-\sqrt{3}\right)=\sqrt{3}\cdot4\sqrt{3}=12\)
\(=\left(\sqrt{3}\cdot\sqrt{4}+\sqrt{9}\cdot\sqrt{3}-\sqrt{3}\right)\cdot\sqrt{3}\\ =3\cdot\left(2+3-1\right)=12\)