Violympic toán 7
Các câu hỏi tương tự
\(\dfrac{\sqrt{\dfrac{9}{4}-3^{-1}+2018^0}}{25\%+1\dfrac{1}{4}-1,3}-\dfrac{\left(\dfrac{-1}{2}\right)^2-\sqrt{\dfrac{4}{9}}+0,4}{0,6-\dfrac{2}{3}.\left(\dfrac{-1}{4}-\dfrac{1}{2}\right)}\)
Tính
a) \(2\sqrt{\dfrac{25}{16}}-3\sqrt{\dfrac{49}{36}}+4\sqrt{\dfrac{81}{64}}\)
b) \(\left(3\sqrt{2}\right)^2-\left(4\sqrt{\dfrac{1}{2}}\right)^2+\dfrac{1}{16}.\left(\sqrt{\dfrac{3}{4}}\right)^2\)
c) \(\dfrac{2}{3}\sqrt{\dfrac{81}{16}}-\dfrac{3}{4}\sqrt{\dfrac{64}{9}}+\dfrac{7}{5}.\sqrt{\dfrac{25}{196}}\)
1) \(25^{10}.\left(\dfrac{1}{5}\right)^{20}+\left(\dfrac{-3}{4}\right)^8.\left(\dfrac{-4}{3}\right)^8-2018^0\)
2) \(\left(\dfrac{5}{2}-\dfrac{4}{3}\right).\dfrac{6}{7}+\left(\dfrac{-3}{2}\right)^5:\left(\dfrac{-3}{2}\right)^3\)
3) \(\dfrac{4^5.9^4-2.6^9}{3^8.2^{10}+6^8.20}\)
1. Giải a,sqrt{4}-sqrt{9x}+sqrt{25x}8 b,sqrt{dfrac{1}{4x}}+sqrt{dfrac{1}{9x}}-sqrt{dfrac{1}{36x}}dfrac{2}{3}
2. Adfrac{1}{sqrt{1cdot2018}}+dfrac{1}{sqrt{2cdot2017}}+...+dfrac{1}{sqrt{kleft(2018-k+1right)}}+...+dfrac{1}{sqrt{2018cdot1}}
So sánh A với 2cdotdfrac{2018}{2019}
3.Cho abc201. Tínhdfrac{201a}{ab+201+a+201}+dfrac{b}{cb+b+201}+dfrac{c}{ac+c+1}
4.Bleft(dfrac{1-x^3}{1-x}+xright)cdotleft(dfrac{1+x^3}{1+x}-xright) a, Rút gọn B b, tìm x đ...
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1. Giải \(a,\sqrt{4}-\sqrt{9x}+\sqrt{25x}=8\) \(b,\sqrt{\dfrac{1}{4x}}+\sqrt{\dfrac{1}{9x}}-\sqrt{\dfrac{1}{36x}}=\dfrac{2}{3}\)
2. \(A=\dfrac{1}{\sqrt{1\cdot2018}}+\dfrac{1}{\sqrt{2\cdot2017}}+...+\dfrac{1}{\sqrt{k\left(2018-k+1\right)}}+...+\dfrac{1}{\sqrt{2018\cdot1}}\)
So sánh A với \(2\cdot\dfrac{2018}{2019}\)
3.Cho abc=201. Tính\(\dfrac{201a}{ab+201+a+201}+\dfrac{b}{cb+b+201}+\dfrac{c}{ac+c+1}\)
4.\(B=\left(\dfrac{1-x^3}{1-x}+x\right)\cdot\left(\dfrac{1+x^3}{1+x}-x\right)\) a, Rút gọn B b, tìm x để B=64
5. Tìm x: \(\left|x-2\right|-2\left|x+1\right|=3-2\left(1-2x\right)\)
\(\dfrac{\left(13\dfrac{1}{4}-2\dfrac{5}{27}-10\dfrac{5}{6}\right).230\dfrac{1}{25}+46\dfrac{3}{4}}{\left(1\dfrac{3}{10}+\dfrac{10}{3}\right):\left(12\dfrac{1}{3}-14\dfrac{2}{7}\right)}\)
\(\dfrac{\left(1+2+3+...+99+100\right)\left(\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{7}-\dfrac{1}{9}\right)\left(63.1,2-21.3,6\right)}{1-2+3-4+.....+99-100}\)
bài 1: tính
a) dfrac{5^4.20^4}{25^5.4^5} b)3,5-left(-dfrac{2}{7}right) c)left(dfrac{11}{12}:dfrac{33}{16}right).dfrac{3}{5} d)15.left(-dfrac{2}{3}right)^2.-dfrac{7}{3} e)left(dfrac{9}{25}-2.8right):left(3dfrac{4}{5}+0,2right) g)dfrac{21}{47}+dfrac{9}{45}+dfrac{26}{47}+dfrac{4}{5} h)dfrac{15}{12}+dfrac{5}{13}-dfrac{3}{12}-dfrac{18}{13} j)12.left(-dfrac{2}{3}right)^2+dfrac{4}{3} k)dfrac{13}{25}+dfrac{6}{41}-dfrac{38}{25}+dfrac{35}{41}-dfrac{1}{2} l)12,5.left(-dfrac{5}{7}right)+1,5.left(-...
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bài 1: tính
a) \(\dfrac{5^4.20^4}{25^5.4^5}\) b)3,5-\(\left(-\dfrac{2}{7}\right)\) c)\(\left(\dfrac{11}{12}:\dfrac{33}{16}\right).\dfrac{3}{5}\) d)\(15.\left(-\dfrac{2}{3}\right)^2.-\dfrac{7}{3}\) e)\(\left(\dfrac{9}{25}-2.8\right):\left(3\dfrac{4}{5}+0,2\right)\) g)\(\dfrac{21}{47}+\dfrac{9}{45}+\dfrac{26}{47}+\dfrac{4}{5}\) h)\(\dfrac{15}{12}+\dfrac{5}{13}-\dfrac{3}{12}-\dfrac{18}{13}\) j)12.\(\left(-\dfrac{2}{3}\right)^2+\dfrac{4}{3}\) k)\(\dfrac{13}{25}+\dfrac{6}{41}-\dfrac{38}{25}+\dfrac{35}{41}-\dfrac{1}{2}\) l)12,5.\(\left(-\dfrac{5}{7}\right)+1,5.\left(-\dfrac{5}{7}\right)\) m)\(\sqrt{\dfrac{64}{25}}.3\dfrac{1}{2}-\dfrac{3}{5}.3\dfrac{1}{2}\)
Thực hiện phép tính:
\(A=\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
\(B=\dfrac{1-\dfrac{1}{\sqrt{49}}+\dfrac{1}{49}-\dfrac{1}{\left(7\sqrt{7}\right)^2}}{\dfrac{\sqrt{64}}{2}-\dfrac{4}{7}+\dfrac{2^2}{7^2}-\dfrac{4}{343}}\)
1) \(\left(\dfrac{1}{3}\right)^{50}.90^{25}-\dfrac{2}{3}:4\)
2) \(10.\sqrt{0,01}.\sqrt{\dfrac{16}{9}}+\sqrt{49}-\dfrac{1}{6}.\sqrt{4}\)
Tính hợp lí nếu có thể
a) \(\left(\dfrac{5}{7}-\dfrac{7}{5}\right)-\left[\dfrac{1}{2}-\left(-\dfrac{2}{7}-\dfrac{1}{10}\right)\right]\)
b) \(\dfrac{2}{15}:\left(-5\dfrac{4}{5}\right).2\dfrac{5}{12}+\sqrt{1\dfrac{9}{16}}:\left(-\dfrac{3}{4}\right)\)