rut gon bt ;
a) \(\left(\sqrt{27}-2\sqrt{17}+\sqrt{7}\right)\cdot\sqrt{7}+7\sqrt{8}\)
b) \(\sqrt{3-2\sqrt{2}}+\sqrt{3+2\sqrt{2}}\)
c) \(9\sqrt{2}-4\sqrt{8}-\sqrt{50}+2\sqrt{32}\)
d) \(\sqrt{3-2\sqrt{2}}-\sqrt{6+4\sqrt{2}}\)
K
Khách
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Những câu hỏi liên quan
20 tháng 4 2020
Ta có: \(\left(a+2\right)^2-\left(a+2\right)\left(a-2\right)\)
\(=\left(a+2\right)\left(a+2-a+2\right)\)
\(=\left(a+2\right)\cdot4=4a+8\)
S
6 tháng 7 2016
P=2.(5^2-1).(5^2+1).(5^4+1).(5^8+1).(5^16+1)
=2.(5^4-1).(5^4+1).(5^8+1).(5^16+1)
= 2.(5^8-1).(5^8+1).(5^16+1)
= 2.(5^16-1).(5^16+1)
= 2.(5^32-1)
25 tháng 7 2016
1)P= 12(5^2+1)(5^4+1)(5^8+1)(5^16+1)
=> 2P = 24(5^2+1)(5^4+1)(5^8+1)(5^16+1)
=(5^2-1)(5^2+1)(5^4+1)(5^8+1)(5^16+1)
=(5^4-1)(5^4+1)(5^8+1)(5^16+1)
=(5^8-1)(5^8+1)(5^16+1)
=(5^16-1)(5^16+1)
=5^32-1
=> P = (5^32-1)/2
BT
0
DN
1
24 tháng 9 2022
\(C=\dfrac{\sqrt{\dfrac{4x^2+4x+1}{x}}}{\sqrt{x}\cdot\left|2x^2-x-1\right|}=\dfrac{\left|2x+1\right|}{\sqrt{x}}\cdot\dfrac{1}{\sqrt{x}\cdot\left|\left(x-1\right)\left(2x+1\right)\right|}\)
\(=\dfrac{1}{x\left|x-1\right|}\)
\(a,\left(\sqrt{27}-2\sqrt{17}+\sqrt{7}\right)\cdot\sqrt{7}+7\sqrt{8}\)
\(=3\sqrt{21}-2\sqrt{119}+7+7\sqrt{8}\)
Đề sai chăng???
\(b,\sqrt{3-2\sqrt{2}}+\sqrt{3+2\sqrt{2}}\)
\(=\sqrt{2-2\sqrt{2}+1}+\sqrt{2+2\sqrt{2}+1}\)
\(=\sqrt{\left(\sqrt{2}-1\right)^2}+\sqrt{\left(\sqrt{2}+1\right)^2}\)
\(=\sqrt{2}-1+\sqrt{2}+1\)
\(=2\sqrt{2}\)
\(c,9\sqrt{2}-4\sqrt{8}-\sqrt{50}+2\sqrt{32}\)
\(=9\sqrt{2}-8\sqrt{2}-5\sqrt{2}+8\sqrt{2}\)
\(=\sqrt{2}\left(9-8-5+8\right)\)
\(=4\sqrt{2}\)
\(d,\sqrt{3-2\sqrt{2}}-\sqrt{6+4\sqrt{2}}\)
\(=\sqrt{2-2\sqrt{2}+1}-\sqrt{4+2.2\sqrt{2}+2}\)
\(=\sqrt{\left(\sqrt{2}-1\right)^2}-\sqrt{\left(2+\sqrt{2}\right)^2}\)
\(=\sqrt{2}-1-2-\sqrt{2}\)
\(=-3\)