a) \(9\cdot3^2\cdot\dfrac{1}{81}=\dfrac{9\cdot9}{81}=\dfrac{81}{81}=1\)
b) \(2\dfrac{1}{2}+\dfrac{4}{7}:\left(-\dfrac{8}{9}\right)\)\(=\dfrac{5}{2}+\dfrac{4}{7}\cdot\left(-\dfrac{9}{8}\right)\)
\(=\dfrac{5}{2}-\dfrac{9}{14}\)\(=\dfrac{35}{14}-\dfrac{9}{14}=\dfrac{26}{14}=\dfrac{13}{7}\)
c) \(3,75\cdot7,2+2,8\cdot3,75=3,75\left(7,2+2,8\right)=3,75\cdot10=37,5\)
Tính:
\(\left(\dfrac{9}{25}-2.18\right):\left(3\dfrac{4}{5}+0,2\right)\)
\(\dfrac{3}{8}.19\dfrac{1}{3}\dfrac{3}{8}.33\dfrac{1}{3}\)
\(15.\left(-\dfrac{2}{3}\right)^2-\dfrac{7}{3}\)
\(\dfrac{1}{2}\sqrt{64}-\sqrt{\dfrac{4}{25}}+\left(-1\right)^{2007}\)
\(\left(-\dfrac{5}{2}\right)^2:\left(-15\right)-\left(0,45+\dfrac{3}{4}\right).\left(-1\dfrac{5}{9}\right)\)
\(\left(\dfrac{-1}{3}\right)-\left(\dfrac{-3}{5}\right)^0+\left(1-\dfrac{1}{2}\right)^2:2\)
\(\left(\dfrac{1}{2}\right)^{15}.\left(\dfrac{1}{4}\right)^{20}\)
\(\dfrac{5^4.20}{25^5.4^5}\)
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)\(\dfrac{2^9.4^{10}}{8^8}\)
Thực hiện phép tính:(hợp lý nếu có thể)
a, \(5.\dfrac{5}{27}+\dfrac{7}{23}+0,5.\dfrac{5}{7}+\dfrac{16}{23}+\dfrac{1}{2}\)
b, \(25\dfrac{1}{6}:\dfrac{-4}{5}-45\dfrac{1}{6}:\dfrac{-4}{5}\)
c, \(25.\left(\dfrac{-1}{5}\right)^3+\dfrac{1}{5}-2.\left(\dfrac{-1}{2}\right)^2-\dfrac{1}{2}\)
d, \(-\left(251.3+281\right)+3.251-\left(1-281\right)\)
e, \(\left(0,75-\dfrac{1}{4}\right):\left(-5\right)+\dfrac{1}{15}-\left(-\dfrac{1}{5}\right):\left(-3\right)\)
f, \(\sqrt{\dfrac{4}{81}}:\sqrt{\dfrac{25}{81}}-1\dfrac{2}{5}\)
a) [\(2^{-2}\) + 0,75] . \(3\dfrac{3}{5}\) - \(\sqrt{\dfrac{36}{25}}\) : \(\left(-1\dfrac{4}{5}\right)\) + 4 . \(\left(-\dfrac{1}{2015}\right)^0\)
b) \(\left(-\dfrac{3}{5}\right)^2\) . \(\left(0,6-\left|\dfrac{1}{2}-\dfrac{1}{5}\right|\right)\) - \(\sqrt{\left(\dfrac{-3}{8}\right)^2}\) : \(1\dfrac{1}{8}\)
c) \(\sqrt{0,49}\) : \(\sqrt{\dfrac{16}{25}}\) + \(\sqrt{\dfrac{4}{81}}\) : \(\sqrt{\dfrac{25}{81}}\) - \(\left(-\dfrac{1}{2}\right)^3\)
d) \(19\dfrac{1}{3}\) : \(\dfrac{7}{3}\) - \(33\dfrac{1}{3}\) : \(\dfrac{7}{3}\) - \(\left|-\dfrac{2}{7}\right|\)
e) \(\dfrac{4^6.9^5+6^9.120}{-6^{11}-8^4.3^{12}}\)
Các bạn giúp mình với
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/ \(\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
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) \(\left[2^3.\left(-\dfrac{1}{2}\right)^3+\dfrac{1}{2}\right]+\left[\dfrac{25}{22}+\dfrac{6}{25}-\dfrac{3}{22}+\dfrac{19}{25}+\dfrac{1}{2}\right]\)
Cần giúp nhanh vs
Bài 1. Tìm x
a) \(\left|x+\dfrac{7}{4}\right|=\dfrac{1}{2}\)
b) \(\left|2x+1\right|-\dfrac{2}{5}=\dfrac{1}{3}\)
c) \(3x.\left(x+\dfrac{2}{3}\right)=0\)
d) \(x+\dfrac{1}{3}=\dfrac{2}{5}-\left(-\dfrac{1}{3}\right)\)
Bài 2. Tính nhanh
\(A=\dfrac{1}{100}-\dfrac{1}{100.99}-\dfrac{1}{99.98}-\dfrac{1}{98.97}-....-\dfrac{1}{3.2}-\dfrac{1}{2.1}\)
Câu 1.Thực hiện phép tính:
a) -1\(\dfrac{5}{7}.15+\dfrac{2}{7}.\left(-15\right)+\left(-105\right).\left(\dfrac{2}{3}-\dfrac{4}{5}+\dfrac{1}{7}\right)\)
b) \(\dfrac{2^{15}.9^4}{6^6.8^3}\)
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) \(15\dfrac{1}{4}:\left(\dfrac{-5}{7}\right)-25\dfrac{1}{4}:\left(\dfrac{-5}{7}\right)\)
