Tính: \(\sqrt{1}\) - \(\sqrt{4}\) + \(\sqrt{9}\) - \(\sqrt{16}\) + \(\sqrt{25}\) - \(\sqrt{36}\) +..............- \(\sqrt{400}\)
(Giải nhanh nhé,gấp lắm)
Những câu hỏi liên quan
Tính \(\sqrt{1}-\sqrt{4}+\sqrt{9}-\sqrt{16}+\sqrt{25}-\sqrt{36}+.....-\sqrt{400}\)
EEEEEEEEEEEEEE ĐÉ
\(\sqrt{1}-\sqrt{4}+\sqrt{9}-\sqrt{16}+\sqrt{25}-\sqrt{36}+...-\sqrt{400}\)
\(=1-2+3-4+5-6+...-400\)
\(=\left(1-2\right)+\left(3-4\right)+\left(5-6\right)+...+\left(399-400\right)\)
\(=-1+\left(-1\right)+\left(-1\right)+...+\left(-1\right)\) (200 số hạng -1)
\(=\left(-1\right).200=-200\)
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\(\sqrt{1}\) - \(\sqrt{4}\) + \(\sqrt{9}\) - \(\sqrt{16}\)+ \(\sqrt{25}\)- \(\sqrt{36}\)+ ... - \(\sqrt{400}\)
5\(\sqrt{16}\)-4\(\sqrt{9}\)+\(\sqrt{25}\)-0,3\(\sqrt{400}\)
E = \(5\sqrt{16}-4\sqrt{9}+\sqrt{25}-0,3\sqrt{400}\)
2) giải pt
a) \(\sqrt{4-2x}=5\)
b) \(\sqrt{25\left(x+1\right)}+\sqrt{9x+9}=16\)
c) \(\sqrt{4x^2+12x+9}=4\)
giúp mk vs ạ mk cần gấp
a) ĐKXĐ: x <= 2
pt --> 4 - 2x = 25 <=> x = -21/2 (thỏa)
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b) ĐKXĐ: x >= -1
pt <=> 8sqrt(x + 1)=16 <=> sqrt(x+1)=2 --> x + 1 = 4 <=> x = 3
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Xem thêm câu trả lời
(\(\sqrt{\dfrac{9}{4}}\) - \(\sqrt{9}\) ) . \(\sqrt{1\dfrac{9}{16}}\)
Tính nhanh giúp mik nha, mik cần gấp
\(=\left(\dfrac{3}{2}-3\right).\sqrt{\dfrac{25}{16}}=\left(-\dfrac{3}{2}\right).\dfrac{5}{4}=-\dfrac{15}{8}\)
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a,sqrt{1}+sqrt{9}+sqrt{25}+sqrt{49}+sqrt{81} csqrt{0,04}+sqrt{0,09}+sqrt{0,16}
b,sqrt{dfrac{1}{4}}+sqrt{dfrac{1}{9}}+sqrt{dfrac{1}{36}}+sqrt{dfrac{1}{16}} esqrt{2^2}+sqrt{4^2}+sqrt{left(-6^2right)}+sqrt{left(-8^2right)}
j,sqrt{1,44}-sqrt{1,69}+sqrt{1,96}
g, sqrt{dfrac{4}{25}}+sqrt{dfrac{25}{4}}+sqrt{dfrac{81}{100}}+sqrt{dfrac{9}{16}}
dsqrt{81}-sqrt{64}+sq...
Đọc tiếp
a,\(\sqrt{1}+\sqrt{9}+\sqrt{25}+\sqrt{49}+\sqrt{81}\) c\(\sqrt{0,04}+\sqrt{0,09}+\sqrt{0,16}\)
b,\(\sqrt{\dfrac{1}{4}}+\sqrt{\dfrac{1}{9}}+\sqrt{\dfrac{1}{36}}+\sqrt{\dfrac{1}{16}}\) e\(\sqrt{2^2}+\sqrt{4^2}+\sqrt{\left(-6^2\right)}+\sqrt{\left(-8^2\right)}\)
j,\(\sqrt{1,44}-\sqrt{1,69}+\sqrt{1,96}\)
g, \(\sqrt{\dfrac{4}{25}}+\sqrt{\dfrac{25}{4}}+\sqrt{\dfrac{81}{100}}+\sqrt{\dfrac{9}{16}}\)
d\(\sqrt{81}-\sqrt{64}+\sqrt{49}\)
a)\(\sqrt{1}\)+\(\sqrt{9}\)+\(\sqrt{25}\)+\(\sqrt{49}\)+\(\sqrt{81}\)
=1+3+5+7+9
=25
b)=\(\dfrac{1}{2}\)+\(\dfrac{1}{3}\)+\(\dfrac{1}{6}\)+\(\dfrac{1}{4}\)
=\(\dfrac{6}{12}\)+\(\dfrac{4}{12}\)+\(\dfrac{2}{12}\)+\(\dfrac{3}{12}\)
=\(\dfrac{15}{12}\)
c) =0,2+0.3+0,4
= 0.9
d) =9-8+7
=8
j) =1,2-1,3+1.4
= (-0,1)+1,4
=1,4
g) \(\dfrac{2}{5}\)+\(\dfrac{5}{2}\)+\(\dfrac{9}{10}\)+\(\dfrac{3}{4}\)
= (\(\dfrac{4}{10}\)+\(\dfrac{15}{10}\)+\(\dfrac{9}{10}\))+\(\dfrac{3}{4}\)
= \(\dfrac{14}{5}\)+\(\dfrac{3}{4}\)
=\(\dfrac{56}{20}\)+\(\dfrac{15}{20}\)
= \(\dfrac{71}{20}\)
Nhớ tick cho mk nha~
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\(5\sqrt{16}-4\sqrt{9}+\sqrt{25}-\sqrt{400}\)
\(5\sqrt{16}-4\sqrt{9}+\sqrt{25}-\sqrt{400}\)
\(=5.4-4.3+5-20\)
\(=20-12+5-20\)
\(=-7\)
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5√16−4√9+√25−√400
=5.4−4.3+5−20
=20−12+5−20
=8+5-20
=13-20
=-7
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giải phương trình
a)\(\sqrt{x-1}+\sqrt{4x-4}-\sqrt{25x-25}+2=0\)
b)\(\sqrt{16x+16}-\sqrt{9x+9}+\sqrt{4x+4}+\sqrt{x+1}=16\)
c)\(\sqrt{4x+20}+\sqrt{x+5}-\dfrac{1}{3}\sqrt{9x+45}=4\)
d)\(\dfrac{1}{3}\sqrt{2x}-\sqrt{8x}+\sqrt{18x}-10=2\)
a) \(\sqrt{x-1}+\sqrt{4x-4}-\sqrt{25x-25}+2=0\) (ĐK: \(x\ge1\))
\(\Leftrightarrow\sqrt{x-1}+\sqrt{4\left(x-1\right)}-\sqrt{25\left(x-1\right)}+2=0\)
\(\Leftrightarrow\sqrt{x-1}+2\sqrt{x-1}-5\sqrt{x-1}+2=0\)
\(\Leftrightarrow-2\sqrt{x-1}=-2\)
\(\Leftrightarrow\sqrt{x-1}=\dfrac{2}{2}\)
\(\Leftrightarrow\sqrt{x-1}=1\)
\(\Leftrightarrow x-1=1\)
\(\Leftrightarrow x=2\left(tm\right)\)
b) \(\sqrt{16x+16}-\sqrt{9x+9}+\sqrt{4x+4}+\sqrt{x+1}=16\) (ĐK: \(x\ge-1\))
\(\Leftrightarrow\sqrt{16\left(x+1\right)}-\sqrt{9\left(x+1\right)}+\sqrt{4\left(x+1\right)}+\sqrt{x+1}=16\)
\(\Leftrightarrow4\sqrt{x+1}-3\sqrt{x+1}+2\sqrt{x+1}+\sqrt{x+1}=16\)
\(\Leftrightarrow4\sqrt{x+1}=16\)
\(\Leftrightarrow\sqrt{x+1}=4\)
\(\Leftrightarrow x+1=16\)
\(\Leftrightarrow x=15\left(tm\right)\)
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