Ôn tập chương 1
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tính A = \(\dfrac{3}{1^2.2^2}+\dfrac{5}{2^2.3^2}\)
1) Tính dfrac{7^4.3-7^3}{7^4.6-7^3.2} ; dfrac{10^3+5.10^2+5}{6^3+3.6^2+3^2} ; E1+dfrac{1}{3}+dfrac{1}{3^2}+...+dfrac{1}{3^{100}} 2) Tìm x biếtdfrac{1}{1.2}+dfrac{1}{2.3}+dfrac{1}{3.4}+...+dfrac{1}{x.left(x+1right)} ; 3^{x+1}+3^{x+3}810 MN ƠI ! GIÚP MIK VS .
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1) Tính
\(\dfrac{7^4.3-7^3}{7^4.6-7^3.2}\) ; \(\dfrac{10^3+5.10^2+5}{6^3+3.6^2+3^2}\) ; \(E=1+\dfrac{1}{3}+\dfrac{1}{3^2}+...+\dfrac{1}{3^{100}}\)
2) Tìm x biết
\(\dfrac{1}{1.2}+\dfrac{1}{2.3}+\dfrac{1}{3.4}+...+\dfrac{1}{x.\left(x+1\right)}\) ; \(3^{x+1}+3^{x+3}=810\)
MN ƠI ! GIÚP MIK VS > . <
Thuc hien phep tinh;
a/ 1dfrac{4}{23}+dfrac{5}{21}-dfrac{4}{23}+0,5+dfrac{16}{21}
b/ left(dfrac{1}{25}+dfrac{1}{5}+1right):left(dfrac{1}{25}-dfrac{1}{5}-1right)
c/ dfrac{dfrac{1}{9}-dfrac{1}{7}-dfrac{1}{11}}{dfrac{4}{9}-dfrac{4}{7}-dfrac{4}{11}}+ dfrac{0,6-dfrac{3}{25}-dfrac{3}{125}-dfrac{3}{625}}{dfrac{4}{5}-0,16-dfrac{4}{125}-dfrac{4}{625}}
d/ dfrac{2^{12}.3^5-4^6.9^2}{left(2^2.3right)^6+8^4.3^5}-dfrac{5^{10}.7^3-25^5.49^2}{left(125.7right)^3+5^9.14^3}
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Thuc hien phep tinh;
a/ \(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
b/ \(\left(\dfrac{1}{25}+\dfrac{1}{5}+1\right):\left(\dfrac{1}{25}-\dfrac{1}{5}-1\right)\)
c/ \(\dfrac{\dfrac{1}{9}-\dfrac{1}{7}-\dfrac{1}{11}}{\dfrac{4}{9}-\dfrac{4}{7}-\dfrac{4}{11}}\)+ \(\dfrac{0,6-\dfrac{3}{25}-\dfrac{3}{125}-\dfrac{3}{625}}{\dfrac{4}{5}-0,16-\dfrac{4}{125}-\dfrac{4}{625}}\)
d/ \(\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
Tính:left(dfrac{9}{25}-2.18right):left(3dfrac{4}{5}+0,2right) dfrac{3}{8}.19dfrac{1}{3}dfrac{3}{8}.33dfrac{1}{3} 15.left(-dfrac{2}{3}right)^2-dfrac{7}{3} dfrac{1}{2}sqrt{64}-sqrt{dfrac{4}{25}}+left(-1right)^{2007} left(-dfrac{5}{2}right)^2:left(-15right)-left(0,45+dfrac{3}{4}right).left(-1dfrac{5}{9}right)left(dfrac{-1}{3}right)-left(dfrac{-3}{5}right)^0+left(1-dfrac{1}{2}right)^2:2 left(dfrac{1}{2}right)^{15}.left(dfrac{1}{4}right)^{20}dfrac{5^4.20}{25^5.4^5}
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Tính:
\(\left(\dfrac{9}{25}-2.18\right):\left(3\dfrac{4}{5}+0,2\right)\)
\(\dfrac{3}{8}.19\dfrac{1}{3}\dfrac{3}{8}.33\dfrac{1}{3}\)
\(15.\left(-\dfrac{2}{3}\right)^2-\dfrac{7}{3}\)
\(\dfrac{1}{2}\sqrt{64}-\sqrt{\dfrac{4}{25}}+\left(-1\right)^{2007}\)
\(\left(-\dfrac{5}{2}\right)^2:\left(-15\right)-\left(0,45+\dfrac{3}{4}\right).\left(-1\dfrac{5}{9}\right)\)
\(\left(\dfrac{-1}{3}\right)-\left(\dfrac{-3}{5}\right)^0+\left(1-\dfrac{1}{2}\right)^2:2\)
\(\left(\dfrac{1}{2}\right)^{15}.\left(\dfrac{1}{4}\right)^{20}\)
\(\dfrac{5^4.20}{25^5.4^5}\)
Tính hợp lí :
a) \(19\dfrac{1}{3}.\dfrac{3}{7}-33\dfrac{1}{3}\)
b) \(9.\left(\dfrac{1}{2}\right)^2+\dfrac{1}{3}\)
c) \(15\dfrac{1}{4}:\left(\dfrac{-5}{7}\right)-25\dfrac{1}{4}:\left(\dfrac{-5}{7}\right)\)
thực hiện phép tính (tính hợp lí nếu có thể)
1) left(-dfrac{1}{2}right)^2:dfrac{1}{4}-2.left(dfrac{-1}{2}right)^3+sqrt{4}
2) 3-left(dfrac{-6}{7}right)^0+sqrt{9}:2
3) left(-2right)^3+dfrac{1}{2}:dfrac{1}{8}-sqrt{25}+left|-64right|
4) left(-dfrac{1}{2}right)^4+left|-dfrac{2}{3}right|-2007^0
5) dfrac{left(0,4-dfrac{2}{9}+dfrac{2}{11}right)}{1,4-dfrac{7}{9}+dfrac{7}{11}}-dfrac{dfrac{1}{3}-0,25+dfrac{1}{5}}{1dfrac{1}{6}-0,875+0,7}
6) left[2^3.left(-dfrac{1}{2}right)^3+dfrac{1}{2}right]+left[dfr...
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thực hiện phép tính (tính hợp lí nếu có thể)
1) \(\left(-\dfrac{1}{2}\right)^2:\dfrac{1}{4}-2.\left(\dfrac{-1}{2}\right)^3+\sqrt{4}\)
2) \(3-\left(\dfrac{-6}{7}\right)^0+\sqrt{9}:2\)
3) \(\left(-2\right)^3+\dfrac{1}{2}:\dfrac{1}{8}-\sqrt{25}+\left|-64\right|\)
4) \(\left(-\dfrac{1}{2}\right)^4+\left|-\dfrac{2}{3}\right|-2007^0\)
5) \(\dfrac{\left(0,4-\dfrac{2}{9}+\dfrac{2}{11}\right)}{1,4-\dfrac{7}{9}+\dfrac{7}{11}}-\dfrac{\dfrac{1}{3}-0,25+\dfrac{1}{5}}{1\dfrac{1}{6}-0,875+0,7}\)
6) \(\left[2^3.\left(-\dfrac{1}{2}\right)^3+\dfrac{1}{2}\right]+\left[\dfrac{25}{22}+\dfrac{6}{25}-\dfrac{3}{22}+\dfrac{19}{25}+\dfrac{1}{2}\right]\)
Bài 1:
a) \(\left(2-\sqrt{3}\right).\left(2+\sqrt{3}\right)+\sqrt{2}.\dfrac{\sqrt{2^5}}{1-\sqrt{9}}\)
b)\(\left(\dfrac{1}{1.2}+\dfrac{1}{2.3}+\dfrac{1}{3.4}+...+\dfrac{1}{49.50}\right).\dfrac{49}{50}\)
Cảm ơn trước nha
a)dfrac{5}{15}+dfrac{14}{25}-dfrac{12}{9}+dfrac{2}{7}+dfrac{11}{25}
b)left(dfrac{3}{7}-dfrac{5}{2}-dfrac{3}{5}right)-left(-dfrac{4}{7}-dfrac{3}{2}+dfrac{2}{5}right)
c)left(dfrac{2}{5}right)^2+5dfrac{1}{2}.left(4,5-2right)+dfrac{2^3}{left(-4right)}
d)left(-dfrac{1}{2}right)^2:dfrac{1}{4}-2.left(-dfrac{1}{2}right)^3
e)sqrt{16}.1dfrac{3}{4}+dfrac{1}{4}-7
f)dfrac{2^9.4^{10}}{8^8}
Đọc tiếp
a)\(\dfrac{5}{15}+\dfrac{14}{25}-\dfrac{12}{9}+\dfrac{2}{7}+\dfrac{11}{25}\)
b)\(\left(\dfrac{3}{7}-\dfrac{5}{2}-\dfrac{3}{5}\right)-\left(-\dfrac{4}{7}-\dfrac{3}{2}+\dfrac{2}{5}\right)\)
c)\(\left(\dfrac{2}{5}\right)^2+5\dfrac{1}{2}.\left(4,5-2\right)+\dfrac{2^3}{\left(-4\right)}\)
d)\(\left(-\dfrac{1}{2}\right)^2:\dfrac{1}{4}-2.\left(-\dfrac{1}{2}\right)^3\)
e)\(\sqrt{16}.1\dfrac{3}{4}+\dfrac{1}{4}-7\)
f)\(\dfrac{2^9.4^{10}}{8^8}\)
tìm x biết
1) dfrac{2}{3}+dfrac{1}{3}:xdfrac{3}{5}
2) left(dfrac{2x}{3}-3right):left(-10right)dfrac{2}{5}
3) 2dfrac{2}{3}:x2dfrac{1}{12}:left(-0,06right)
4) dfrac{3}{7}+dfrac{1}{7}:xdfrac{3}{14}
5) -dfrac{3}{5}.x-dfrac{1}{2}-dfrac{1}{7}
6) dfrac{1}{5}+2x-2dfrac{1}{4}
7)-dfrac{1}{2}:xdfrac{3}{8}:dfrac{9}{16}
8)dfrac{2}{3}:x2dfrac{1}{2}:left(-0,3right)
9) dfrac{x}{3}dfrac{-2}{1,5}
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tìm x biết
1) \(\dfrac{2}{3}+\dfrac{1}{3}:x=\dfrac{3}{5}\)
2) \(\left(\dfrac{2x}{3}-3\right):\left(-10\right)=\dfrac{2}{5}\)
3) \(2\dfrac{2}{3}:x=2\dfrac{1}{12}:\left(-0,06\right)\)
4) \(\dfrac{3}{7}+\dfrac{1}{7}:x=\dfrac{3}{14}\)
5) \(-\dfrac{3}{5}.x-\dfrac{1}{2}=-\dfrac{1}{7}\)
6) \(\dfrac{1}{5}+2x=-2\dfrac{1}{4}\)
7)\(-\dfrac{1}{2}:x=\dfrac{3}{8}:\dfrac{9}{16}\)
8)\(\dfrac{2}{3}:x=2\dfrac{1}{2}:\left(-0,3\right)\)
9) \(\dfrac{x}{3}=\dfrac{-2}{1,5}\)