A=\(\left(\dfrac{1}{2}-1\right)\left(\dfrac{1}{3}-1\right)\left(\dfrac{1}{4}-1\right)...\left(\dfrac{1}{2017}-1\right)\)
B=\(\left(-1\dfrac{1}{2}\right)\left(-1\dfrac{1}{3}\right)\left(-1\dfrac{1}{4}\right)...\left(-1\dfrac{1}{2017}\right)\)
Tính M=A*B
Cho A=\(\left(\dfrac{1}{2}-1\right).\left(\dfrac{1}{3}-1\right).\left(\dfrac{1}{4}-1\right)...\left(\dfrac{1}{2015}-1\right).\left(\dfrac{1}{2016}-1\right).\left(\dfrac{1}{2017}-1\right)\)
B=\(\left(-1\dfrac{1}{2}\right).\left(-1\dfrac{1}{3}\right).\left(-1\dfrac{1}{4}\right)...\left(-1\dfrac{1}{2015}\right).\left(-1\dfrac{1}{2016}\right).\left(-1\dfrac{1}{2017}\right)\)
Tính M=A.B
Tính B=\(\left(1-\dfrac{1}{1+2}\right).\left(1-\dfrac{1}{1+2+3}\right).....\left(1-\dfrac{1}{1+2+3+...+2017}\right)\)
Tính A=\((1-\dfrac{1}{1+2}).\left(1-\dfrac{1}{1+2+3}\right).\left(1-\dfrac{1}{1+2+3+4}\right)...\left(1-\dfrac{1}{1+2+3+..,+2017}\right)\)
tính :
a, \(\left[6.\left(-\dfrac{1}{3}\right)^2-3.\left(-\dfrac{1}{3}\right)+1\right]:\left(-\dfrac{1}{3}-1\right)\)
b, \(\dfrac{\left(\dfrac{2}{3}\right)^3.\left(-\dfrac{3}{4}\right)^2.\left(-1\right)^{2003}}{\left(\dfrac{2}{5}\right)^2.\left(-\dfrac{5}{12}\right)^3}\)
Bài 1. a, Cho A = \(\left(\dfrac{1}{2}-1\right)\left(\dfrac{1}{3}-1\right).....\left(\dfrac{1}{10}-1\right)\)
So sánh A với \(\dfrac{-1}{9}\)
Bài 2. Cho A = \(\left(\dfrac{1}{2}-1\right)\left(\dfrac{1}{3}-1\right)....\left(\dfrac{1}{2008}-1\right)\left(\dfrac{1}{2009}-1\right)\)
B = \(\left(-1\dfrac{1}{2}\right)\left(-1\dfrac{1}{3}\right)....\left(-1\dfrac{1}{2007}\right)\left(-1\dfrac{1}{2008}\right)\)
Tính A . B ?
Tìm x.
\(1,\dfrac{3}{2}\left(x-\dfrac{1}{3}\right)-\dfrac{1}{2}\left(x+\dfrac{1}{2}\right)=\dfrac{1}{4}\)
\(2,3\left(x-2\right)-4\left(x+2\right)=x+2\)
\(3,4x\left(x-1\right)+4x-2\left(x+1\right)=-2\)
\(4,x\left(x+2\right)-3\left(x-1\right)=3\left(x+1\right)\)
a,\(\dfrac{8^{20}+4^{20}}{4^{25}+64^5}\)
b,\(\left(1+\dfrac{2}{3}-\dfrac{1}{4}\right).\left(\dfrac{4}{5}-\dfrac{3}{4}\right)^2\)
c,\(23\dfrac{1}{3}:\left(\dfrac{-5}{7}\right)-13\dfrac{1}{3}:\left(\dfrac{-5}{7}\right)\)
d,1:\(\left(\dfrac{2}{3}-\dfrac{3}{4}\right)^2\)
e,\(\dfrac{45^{10}.5^{20}}{75^{15}}\)
Tính:
\(\left\{\left[\left(6,2:0,31-\dfrac{5}{6}.0,9\right).0,2+0,15\right]:0,2\right\}:\left[\left(2+1\dfrac{4}{11}.0,22:0,1\right).\dfrac{1}{33}\right]\)
b) \(0,4\left(3\right)+0,6\left(2\right).2\dfrac{1}{2}.\left[\left(\dfrac{1}{2}+\dfrac{1}{3}\right):0,5\left(8\right)\right]:\dfrac{50}{53}\)