\(\dfrac{1}{7}-\dfrac{8}{7}:8-3:\dfrac{3}{4}\cdot\left(-2\right)^2\\ =\dfrac{1}{7}-\dfrac{8}{7}\cdot\dfrac{1}{8}-3\cdot\dfrac{4}{3}\cdot4\\ =\dfrac{1}{7}-\dfrac{1}{7}-16\\ =0-16=-16\)
Tìm số nguyên x biết:
a) \(-4\dfrac{3}{5}\) x \(2\dfrac{4}{3}\) \(\le\) x \(\le\) \(-2\dfrac{3}{5}\) : \(1\dfrac{6}{15}\)
b) \(-4\dfrac{1}{3}\) (\(\dfrac{1}{2}-\dfrac{1}{6}\) ) \(\le\) x \(\le\dfrac{2}{3}\left(\dfrac{1}{3}-\dfrac{1}{2}-\dfrac{3}{7}\right)\)
c) \(\dfrac{x+1}{35}+\dfrac{x+2}{34}+\dfrac{x+3}{33}=\dfrac{x+4}{32}+\dfrac{x+5}{31}\dfrac{x+6}{30}\)
\(\dfrac{1}{\begin{matrix}1\times&2\end{matrix}}+\dfrac{1}{\begin{matrix}2\times&3\end{matrix}}+\dfrac{1}{\begin{matrix}3\times&4\end{matrix}}+...........+\dfrac{1}{x\times\left(x+1\right)}=\dfrac{996}{997}\)
tính giá trị biểu thức sau một cách hợp lí :
\(A=\dfrac{-10}{3}+\dfrac{19}{6}.\dfrac{7}{5}-\dfrac{19}{3}.\dfrac{1}{10}+\dfrac{19}{10}.\dfrac{4}{3}\)
\(M=\dfrac{1+2+2^2+2^3+....+2^{2012}}{2^{2014}-2}\)
\(\dfrac{-5}{6}\) + \(\dfrac{8}{3}\) + \(\dfrac{-29}{6}\) ≤ x ≤ \(\dfrac{-1}{2}\) + 2 + \(\dfrac{5}{2}\)
( 2,7x - 1\(\dfrac{1}{2}\)x) : \(\dfrac{2}{7}\)= \(\dfrac{-21}{4}\)
Tìm x thuộc Z,biết:
\(\dfrac{-2}{7}\)<\(\dfrac{x}{3}\)<\(\dfrac{11}{4}\)
\(\dfrac{3}{5}\)-\(\dfrac{2}{7}\) bằng
\(\dfrac{1}{2}\)-x + \(\dfrac{2}{3}\)x -1 = -3\(\dfrac{1}{3}\)
1) Tính
B=(1+\(\dfrac{1}{2}\)).(1+\(\dfrac{1}{3}\)).(\(1+\dfrac{1}{4}\)).....(\(1+\dfrac{1}{99}\))
