Violympic toán 7
Các câu hỏi tương tự
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) \(\dfrac{2}{15}:\left(-5\dfrac{4}{5}\right).2\dfrac{5}{12}+\sqrt{1\dfrac{9}{16}}:\left(-\dfrac{3}{4}\right)\)
\(\dfrac{\left(13\dfrac{1}{4}-2\dfrac{5}{27}-10\dfrac{5}{6}\right).230\dfrac{1}{25}+46\dfrac{3}{4}}{\left(1\dfrac{3}{10}+\dfrac{10}{3}\right):\left(12\dfrac{1}{3}-14\dfrac{2}{7}\right)}\)
\(\dfrac{\left(1+2+3+...+99+100\right)\left(\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{7}-\dfrac{1}{9}\right)\left(63.1,2-21.3,6\right)}{1-2+3-4+.....+99-100}\)
1 tìm x
a,\(\dfrac{1}{4}x-\left|-\dfrac{3}{10}\right|\)
\(\left(\dfrac{2}{5}-\dfrac{7}{10}x\right):1\dfrac{2}{3}=\dfrac{-3}{4}\)
\(\dfrac{7}{16}:\left(\dfrac{x}{4}+\dfrac{9}{2}\right)-1\dfrac{5}{6}=0\)
Thực hiện phép tính
a, A = \(\left(\dfrac{1}{4\times9}+\dfrac{1}{9\times14}+\dfrac{1}{14\times19}+....+\dfrac{1}{44\times49}\right)\times\dfrac{1-3-5-7-....-49}{89}\)
b, B = \(\dfrac{2^{12}\times3^5-4^6\times9^2}{\left(2^2\times3\right)^6+8^4\times3^5}-\dfrac{5^{10}\times7^3-25^5\times49^2}{\left(125\times7\right)^3-5^9\times14^3}\)
1.thực hiện phép tính
a.dfrac{-5}{21}-dfrac{1}{3}+3dfrac{1}{2}.left(dfrac{-2}{3}right)^3
b)-2dfrac{1}{3}+left(dfrac{3}{8}-dfrac{3}{4^{^{ }}}right)^3:dfrac{5}{9}-dfrac{1}{2}
c)left(6-2dfrac{4}{5}right).3dfrac{1}{8}-1dfrac{3}{5}:left(-dfrac{1}{2}right)^2
d)-dfrac{3}{7}.dfrac{5}{9}+dfrac{4}{7}.dfrac{-1}{3}-left(0,5right)^3
e)dfrac{15}{5}-dfrac{2}{17}+dfrac{15}{23}-dfrac{15}{17}+dfrac{4}{19}
Giúp mik nha mai mik phải nộp bài cho thầy rùi nì
Đọc tiếp
1.thực hiện phép tính
a.\(\dfrac{-5}{21}-\dfrac{1}{3}+3\dfrac{1}{2}.\left(\dfrac{-2}{3}\right)^3\)
b)\(-2\dfrac{1}{3}+\left(\dfrac{3}{8}-\dfrac{3}{4^{^{ }}}\right)^3:\dfrac{5}{9}-\dfrac{1}{2}\)
c)\(\left(6-2\dfrac{4}{5}\right).3\dfrac{1}{8}-1\dfrac{3}{5}:\left(-\dfrac{1}{2}\right)^2\)
d)\(-\dfrac{3}{7}.\dfrac{5}{9}+\dfrac{4}{7}.\dfrac{-1}{3}-\left(0,5\right)^3\)
e)\(\dfrac{15}{5}-\dfrac{2}{17}+\dfrac{15}{23}-\dfrac{15}{17}+\dfrac{4}{19}\)
Giúp mik nha mai mik phải nộp bài cho thầy rùi nì
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(-...
Đọc tiếp
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)\(\sqrt{\dfrac{64}{25}}.3\dfrac{1}{2}-\dfrac{3}{5}.3\dfrac{1}{2}\)
Tinh
\(\dfrac{\left(1+2+3+...+100\right)\left(\dfrac{1}{3}-\dfrac{1}{5}-\dfrac{1}{7}-\dfrac{1}{9}\right)\left(6,3.12-21.36\right)}{\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+...+\dfrac{1}{100}}\)
\(\dfrac{\left(\dfrac{3}{10}-\dfrac{4}{15}-\dfrac{7}{20}\right).\dfrac{5}{9}}{\left(\dfrac{1}{14}+\dfrac{1}{7}-\dfrac{-3}{35}\right)\dfrac{-4}{3}}\)
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) \(\dfrac{2}{3}\sqrt{\dfrac{81}{16}}-\dfrac{3}{4}\sqrt{\dfrac{64}{9}}+\dfrac{7}{5}.\sqrt{\dfrac{25}{196}}\)
Thực hiện phép tính:\(\left(-\dfrac{1}{2}\right)-\left(-\dfrac{3}{5}\right)+\left(-\dfrac{1}{9}\right)+\dfrac{1}{71}-\left(-\dfrac{2}{7}\right)+\dfrac{4}{35}-\dfrac{7}{18}\)