a: \(=\dfrac{3}{2}\left(-21-\dfrac{1}{3}+1+\dfrac{1}{3}\right)=\dfrac{3}{2}\cdot\left(-20\right)=-30\)
b: \(=\dfrac{2018}{2019}\left(13-13-\dfrac{2018}{2019}-\dfrac{1}{2019}\right)=-\dfrac{2018}{2019}\)
Cho \(\dfrac{a}{b}=\dfrac{c}{d}\). CMR:\(\dfrac{\left(a^{2018}+b^{2018}\right)^{2019}}{\left(c^{2018}+d^{2018}\right)^{2019}}=\dfrac{\left(a^{2019}-b^{2019}\right)^{2020}}{\left(c^{2019}+d^{2019}\right)^{2020}}\)
HELP ME!!!!!!! Mình cần gấp mai mình lộp bài rùi
Cho biểu thức
A = \(\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+..........+\dfrac{1}{2019}\)
B = \(\dfrac{2018}{1}+\dfrac{2017}{2}+\dfrac{2016}{3}+.......+\dfrac{1}{2018}\) Chứng tỏ rằng \(\dfrac{B}{A}\)là số nguyên
1) Không dùng máy tính hãy so sánh:
A=\(\dfrac{2016}{2017}+\dfrac{2017}{2018}+\dfrac{2018}{2019}+\dfrac{2019}{2006}\) với 4
2) So sánh A và B biết:
A=\(\left(100^{99}+99^{99}\right)^{100}\)
B=\(\left(100^{100}+99^{100}\right)^{99}\)
3) Chứng tỏ rằng:
\(\left(2003^n+1\right)\left(2003^n+2\right)⋮6\forall n\in N\)
Bài 1: Thực hiện phép tính:
\(A=\left(-\dfrac{1}{125}\right)^{11}:\left(\dfrac{1}{5}\right)^{32}\)
\(B=1+\dfrac{1}{3}+\left(\dfrac{1}{3}\right)^2+....+\left(\dfrac{1}{3}\right)^{2018}\)
\(C=\dfrac{16^3\cdot3^{10}+120\cdot6^9}{4^6\cdot3^{12}+6^{11}}\)
\(D=\left(\dfrac{0.4-\dfrac{2}{9}+\dfrac{2}{11}}{1.4-\dfrac{7}{9}+\dfrac{7}{11}}-\dfrac{\dfrac{1}{3}-0.25+\dfrac{1}{5}}{1\dfrac{1}{6}-0.875+0.7}\right):\dfrac{2017}{2018}\)
\(E=\dfrac{1}{2}+\dfrac{1}{6}+\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}+\dfrac{1}{42}+\dfrac{1}{56}+\dfrac{1}{72}\)
\(G=\dfrac{\left(\dfrac{2}{5}\right)^7\cdot5^7+\left(2\dfrac{1}{4}\right)^3:\left(\dfrac{3}{16}\right)^3}{512+2^7\cdot5^2}:\dfrac{\left(\dfrac{1}{2}\right)^0}{\left(-1\right)^{2017}}\)
Mn ơi giúp e với ........ Em đang cần gấp giúp e với nha!!
Thank you mn nhiều nhiều.....
thực hiện phép tính
a)\(\left(\dfrac{9}{25}-2,18\right):\left(3\dfrac{4}{5}+0,2\right)\)
b)\(\dfrac{3}{8}.19\dfrac{1}{3}-\dfrac{3}{8}.33\dfrac{1}{3}\)
c)\(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
d)\(\dfrac{2^{12}.3^5-4^6.81}{2^2.3^6+8^4.3^5}\)
e)\(4\left(-\dfrac{1}{2}\right)^2-2.\left(\dfrac{-1}{2}\right)^2+3.\left(\dfrac{-1}{2}\right)+1\)
g)\(\sqrt{\dfrac{4}{81}}:\sqrt{\dfrac{25}{81}}-1\dfrac{2}{5}\)
tìm x biết
a) \(\dfrac{1}{2}x+2\dfrac{1}{2}=3\dfrac{1}{2}x-\dfrac{3}{4}\)
b) \(\dfrac{2}{3}x-\dfrac{2}{5}=\dfrac{1}{2}x-\dfrac{1}{3}\)
c) \(\dfrac{1}{3}x+\dfrac{2}{5}\left(x+1\right)=0\)
d) \(\dfrac{2}{3}-\dfrac{1}{3}\left(x-\dfrac{3}{2}\right)-\dfrac{1}{2}\left(2x+1\right)=5\)
e) \(\dfrac{x+2015}{5}+\dfrac{x+2016}{4}=\dfrac{x+2017}{3}+\dfrac{x+2018}{2}\)
tính
a) \(\left[\dfrac{0.8\div\left(\dfrac{4}{5}\cdot1025\right)}{0.64-1}+\dfrac{\left(1.08-\dfrac{2}{25}\right)\div\dfrac{4}{7}}{\left(6\dfrac{5}{7}-3\dfrac{1}{4}\right)\cdot2\dfrac{2}{17}}+\left(1.2\cdot0.5\right)\div\dfrac{4}{5}\right]\)
b) \(\left(0.2\right)^{-3}\left[\left(-\dfrac{1}{5}\right)^{-2}\right]^{-1}+\left[\left(\dfrac{1}{2}\right)^{-3}\right]^{-2}\div\left(2^{-3}\right)^{-1}-\left(0.175\right)^{-2}\)
c) \(2+\dfrac{1}{1+\dfrac{1}{2+\dfrac{1}{1+\dfrac{1}{2}}}}\)
d) \(\dfrac{1}{90}-\dfrac{1}{72}-\dfrac{1}{56}-\dfrac{1}{42}-\dfrac{1}{3}\)
e) \(\left(\dfrac{1}{3}\right)^{-1}-\left(-\dfrac{6}{7}\right)^0+\left(\dfrac{1}{2}\right)^2\div2\)
f) \(\dfrac{\dfrac{1}{3}-\dfrac{1}{7}-\dfrac{1}{13}}{\dfrac{2}{3}-\dfrac{2}{7}-\dfrac{2}{13}}\cdot\dfrac{\dfrac{3}{4}-\dfrac{3}{16}-\dfrac{3}{64}-\dfrac{3}{256}}{1-\dfrac{1}{4}-\dfrac{1}{16}-\dfrac{1}{64}}+\dfrac{5}{8}\)
g) \(\dfrac{1}{-\left(2017\right)\left(-2015\right)}+\dfrac{1}{\left(-2015\right)\left(-2013\right)}+...+\dfrac{1}{\left(-3\right)\cdot\left(-1\right)}\)
h) \(\left(1-\dfrac{1}{1\cdot2}\right)+\left(1-\dfrac{1}{2\cdot3}+...+\left(1-\dfrac{1}{2017\cdot2018}\right)\right)\)
Ai nhanh nhất mình sẽ tick nha
Bài 1 : Tính ( nhanh nếu có thể )
a) ( \(\dfrac{1}{2}\) - 1 ) . ( \(\dfrac{1}{3}\) - 1 ) .. . ( \(\dfrac{1}{2018}\) - 1 )
\(\dfrac{1}{3}\) - \(\dfrac{1}{5}\) + \(\dfrac{1}{7}\) \(\dfrac{6}{5}\) + \(\dfrac{6}{21}\) - \(\dfrac{6}{13}\)
b) 162 . ( ----------------- + -------------------- ) : \(\dfrac{8181}{7979}\)
\(\dfrac{7}{3}\) - \(\dfrac{7}{5}\) + 1 \(\dfrac{7}{5}\) + \(\dfrac{7}{11}\) - \(\dfrac{7}{13}\)
( \(\dfrac{1}{5}\) + \(\dfrac{5}{6}\) - \(\dfrac{9}{10}\) ) . \(\dfrac{3}{5}\) - 0,75 : \(1\dfrac{1}{2}\) - \(1,25^2\)
\(\xrightarrow[\left(1\dfrac{1}{2}\right)^4.\left(-3\dfrac{1}{3}\right)^3.\left(-1\right)^7]{\left(-5\right)^3.\left(-0,9\right)^2}\)
\(\left(\dfrac{1}{2}-\dfrac{7}{13}-\dfrac{1}{3}\right)\) + \(\left(\dfrac{-6}{13}+\dfrac{1}{2}+1\dfrac{1}{3}\right)\)
0,75 + \(\dfrac{2}{5}\) + \(\left(\dfrac{1}{9}-1\dfrac{2}{5}+\dfrac{5}{4}\right)\)
-66 . \(\left(\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{11}\right)\) + 124 . (-37) + 63 . (-124)
