1. a) \(\dfrac{5}{3}\) . \(\dfrac{11}{7}\) - \(\dfrac{5}{7}\) . \(\dfrac{5}{3}\)
b) (0,125)\(^{16}\). (-8)\(^{16}\)
c) \(\dfrac{9^2.9^3}{3^9}\)
d) \(\dfrac{9}{24}\) - \(\dfrac{7}{41}\) + \(\dfrac{15}{24}\) + 0,75 - \(\dfrac{34}{41}\)
e) \(5\dfrac{2}{7}\) . ( \(-\dfrac{1}{3}\)) - \(2\dfrac{2}{7}\) . (\(-\dfrac{1}{3}\))
2. a) \(\dfrac{3}{4}\) + \(\dfrac{2}{3}x\) = \(\dfrac{1}{2}\)
b) (2x - 1)\(^2\) = 25
c) | x + 5 | - 6 = 9
Tính:
a) \(\sqrt{\dfrac{9}{16}}-\dfrac{5}{6}+\dfrac{3}{2}\) b) \(\left(\dfrac{1}{9}+\dfrac{2}{3}\right)^2-\dfrac{5}{3}:\sqrt{25}\)
c)\(\dfrac{5}{11}.\left(-\dfrac{3}{7}\right)+\dfrac{5}{11}.\left(\dfrac{-5}{7}\right)+\left(-\dfrac{8}{7}\right).\dfrac{6}{11}\)
d) \(\dfrac{2^8.2^{18}}{8^5.4^6}\)
a) \(4.\left(-\dfrac{1}{2}\right)^3\)\(-2.\left(-\dfrac{1}{2}\right)^2\)+\(3.\left(-\dfrac{1}{2}\right)\)+1
b) \(8.\sqrt{9}\)\(-\sqrt{64}\)
c) \(\sqrt{\dfrac{9}{16}}\)\(+\dfrac{25}{46}\)\(:\dfrac{5}{23}\)\(-\dfrac{7}{4}\)
đung cho 5 sao
a, 1\(\dfrac{5}{18}\)+\(\dfrac{7}{25}\)-\(\dfrac{5}{18}\)+\(\dfrac{18}{25}\)-0, 75
b, \(\dfrac{2}{5}\).\(\dfrac{1}{3}\)-\(\dfrac{4}{3}\).\(\dfrac{2}{5}\)
c, (\(\dfrac{-1}{4}\)).( 6\(\dfrac{2}{11}\)) + 3 \(\dfrac{9}{11}\).(\(\dfrac{-1}{4}\))
d, 4. (-\(\dfrac{1}{2}\))\(^{3_{ }}\)-\(_{ }\)2. (\(\dfrac{-1}{2}\))\(^2\) + 3. (\(\dfrac{-1}{2}\)) + 1
e, \(\dfrac{1}{6}\)-(\(\dfrac{2}{3}\))\(^2\) + \(\dfrac{5}{18}\)
f, (\(\dfrac{4}{3}\)-\(\dfrac{3}{2}\))\(^2\)- 2.|-\(\dfrac{1}{9}\)| + (-\(\dfrac{5}{18}\))
Số sánh các số hữu tỉ sau :
a,\(\dfrac{3}{7}\) và \(\dfrac{11}{15}\)
b,\(\dfrac{-11}{6}\) và \(\dfrac{-8}{9}\)
c,\(\dfrac{297}{16}\) và \(\dfrac{305}{25}\)
d, \(\dfrac{-205}{317}\) và \(\dfrac{-83}{111}\)
\(\dfrac{help}{me}\)
Bài 1 : Thực hiện phép tính
a) \(\dfrac{19}{12}\) + | \(\dfrac{-5}{2}\) | + ( \(\dfrac{3}{2}\) )2
b) \(\dfrac{2}{11}\) . \(\dfrac{16}{9}\) - \(\dfrac{2}{11}\) . \(\dfrac{7}{9}\)
Bài 2 : Tìm x , biết
\(\dfrac{a}{8}\) = \(\dfrac{b}{3}\) và a - b = 55
Giúp mình với
a,\(\dfrac{-8}{9}\)-(\(\dfrac{6}{5}\)-\(\dfrac{8}{9}\))
b, \(\dfrac{-4}{9}\)+\(\sqrt{\dfrac{9}{16}}\)-\(\dfrac{4}{5}\).\(\dfrac{-1^2}{2}\)+25%
c,\(\dfrac{2}{3}\)+(\(\dfrac{-3}{4}\)).\(\dfrac{4}{9}\)
d,16\(\dfrac{3}{4}\) - (-\(\dfrac{6}{5}\)) - 28\(\dfrac{3}{4}\):(-\(\dfrac{6}{5}\))
cho biểu thúc A=\(\dfrac{3}{4}\)+\(\dfrac{8}{9}\)+\(\dfrac{15}{16}\)+....+\(\dfrac{9999}{10000}\) chứng minh A<99
tinh nhanh
A=\dfrac{1}{3}-\dfrac{3}{4}-\left(\dfrac{-3}{5}\right)+\dfrac{1}{64}-\dfrac{2}{9}-\dfrac{1}{36}+\dfrac{1}{15}
B=\dfrac{1}{3}-\dfrac{3}{5}+\dfrac{5}{7}-\dfrac{7}{9}+\dfrac{9}{11}-\dfrac{11}{3}+\dfrac{13}{15}+\dfrac{11}{15}-\dfrac{9}{11}+\dfrac{7}{9}+\dfrac{7}{9}-\dfrac{5}{7}+\dfrac{3}{3}-\dfrac{1}{3}
giup minh nhe minh dang can gap