Thực hiện phép tính
\(\sqrt{146,5^2-109,5^2+27.256}\)
Rút gọn rồi tính:
a)\(\sqrt{117,5^2-26,5^2-1440}\)
b)\(\sqrt{146,5^2-109,5^2+27.256}\)
a) \(\sqrt{117,5^2-26,5^2-1440}=\sqrt{\left(117,5-26,5\right)\left(117,5+26,5\right)-1440}\)
\(=\sqrt{91.144-1440}=\sqrt{144\left(91-10\right)}=\sqrt{12^2.9^2}=12.9=108\)
b) \(\sqrt{146,5^2-109,5^2+27.256}=\sqrt{\left(146,5-109,5\right)\left(146,5+109,5\right)+27.256}\)
\(=\sqrt{37.256+27.256}=\sqrt{256\left(37+27\right)}=\sqrt{256.64}=\sqrt{16^2.8^2}=16.8=128\)
Rút gọn rồi tính:
a.\(\sqrt{117,5^2-26,5^2-1440}\)
b, \(\sqrt{146,5^2-109,5^2+27.256}\)
Mong mọi người giúp đỡ
\(\sqrt{117,5^2-26,5^2}-1440=-202475\)
\(\sqrt{146,5^2-109,5^2+27,256=}-11816494\)
câu đc của bạn phương thiếu căn ở 1440
câu a đc 108
câu b đc128
Tính:
a, căn 52 . căn 13
b, căn 146,52-109,52+ 27.256
\(a,\sqrt{52}.\sqrt{13}=\sqrt{2^2.13}.\sqrt{13}\)
\(=2\sqrt{13}.\sqrt{13}=2.13=26\)
\(b,\sqrt{146,5^2-109,5^2}+27.256\)
\(=\sqrt{\left(146,6-109,5\right)\left(146,5+109,5\right)}+27.256\)
\(=\sqrt{37.256}+27.256\)
\(=\sqrt{4^2.37}+27.16=4\sqrt{37}+4.4.27\)
\(=4\left(\sqrt{37}+108\right)\)
Tính:
a, căn 52 . căn 13
b, căn 146,52-109,52+ 27.256
Rút gọn rồi tính :
a) \(\sqrt{6,8^2-3,2^2}\)
b) \(\sqrt{21,8^2-18,2^2}\)
c) \(\sqrt{117,5^2-26,5^2-1440}\)
d) \(\sqrt{146,5^2-109,5^2+27.256}\)
\(a=\sqrt{\left(6,8-3,2\right)\left(6,8+3,2\right)}=\sqrt{3,6\left(10\right)}=\sqrt{36}=6\)
a) \(\sqrt{6,8^2-3,2^2}=\sqrt{\left(6,8-3,2\right)\left(6,8+3,2\right)}\)
=\(\sqrt{3,6.10}=\sqrt{36}=6\)
b)\(\sqrt{21,8^2-18,2^2}=\sqrt{\left(21,8-18,2\right)\left(21,8+18,2\right)}\)
=\(\sqrt{3,6.40}=\sqrt{144}=12\)
c)\(\sqrt{117,5^2-26,5^2-1440}=\sqrt{\left(117,5-26,5\right)\left(117,5+26,5\right)-1440}\)
=\(\sqrt{91.144-1440}=\sqrt{144.81}=\sqrt{144}.\sqrt{81}=108\)
d)\(\sqrt{146,5^2-109,5^2+27.256}\)=\(\sqrt{\left(146,5-109,5\right)\left(146,5+109,5\right)+27.256}\)
=\(\sqrt{37.256+\sqrt{27.256}}=\sqrt{64.256}=\sqrt{64}.\sqrt{256}=128\)
Rút gọn rồi tính @@
\(\sqrt{146,5^2-109,5^2+27,256}\)
1.Rút gọn rồi tính:
a) \(\sqrt{117,5^2-26,5^2-1440}\)
b) \(\sqrt{146,5^2-109,5^2+27\times256}\)
2. So sánh:
\(\sqrt{2003}+\sqrt{2005}\)và \(2\sqrt{2004}\)
2)
\(\left(\sqrt{2003}+\sqrt{2005}\right)^2=2003+2005+2\sqrt{2003\times2005}\)\(=4008+2\sqrt{\left(2004-1\right)\left(2004+1\right)}=4008+2\sqrt{2004^2-1}\)
\(\left(\sqrt{2004}+\sqrt{2004}\right)^2=2004+2004+2\sqrt{2004\times2004}\)\(=4008+2\sqrt{2004^2}\)
Ta có \(2004^2>2004^2-1\Rightarrow\sqrt{2004^2}>\sqrt{2004^2-1}\Rightarrow4008+2\sqrt{2004^2}>4008+2\sqrt{2004^2-1}\)
Vậy \(2\sqrt{2004}>\sqrt{2003}+\sqrt{2005}\)
Bài 1:Rút gọn
a,\(\sqrt{117,5^2-26,5^2-1440}\)
b,\(\sqrt{146,5^2-109,5^2+27,256}\)
c,\(\sqrt{9-\sqrt{17}\cdot\sqrt{9+\sqrt{17}}}\)
Tính:
a, \(\sqrt{20}\)*\(\sqrt{72}\)*\(\sqrt{4,9}\)
b,\(\sqrt{\frac{999}{111}}\)
c,\(\sqrt{146,5^2-109,5^2+27256}\)
d,\(\sqrt{\frac{149^2-76^2}{457^2-348^2}}\)
a. =\(\sqrt{20.72.4,9}=\sqrt{2.72.49}=\sqrt{144.49}=12.7=84\)
b. \(\sqrt{\frac{999}{111}}=\sqrt{9}=3\)
c. = \(\sqrt{9472+27256}=\sqrt{36728}\approx191,645\)
d. = \(\sqrt{\frac{\left(149+76\right)\left(149-76\right)}{\left(457+348\right)\left(457-348\right)}}=\sqrt{\frac{225.73}{805.109}}=\sqrt{\frac{3285}{17549}}\approx136,817\)