\(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right).........\left(1-\frac{1}{19}\right).\left(1-\frac{1}{20}\right)\)
\(=\frac{1}{2}.\frac{2}{3}.\frac{3}{4}.\frac{4}{5}...........\frac{18}{19}.\frac{19}{20}=\frac{1.2.3.4.5........19}{2.3.4.5.6.7......20}=\frac{1}{20}\)
{1-1/2}x{1-1/3}x{1-1/4}x....x{1-1/18}x{1-1/19}x{1-1/20} = ?
(1-1/2) x (1-1/3) x (1 -1/4) x ... x (1-1/18) x (1-1/19) x ( 1-1/20)
Bài 1:Tính (1-1/2)x(1-1/3)x(1-1/4)x...x(1-1/18)x(1-1/19)x(1-1/20)
Tính bằng cách nhanh nhất :
a. ( 1-1/2 ) x ( 1 -1/3) x ( 1-1/4) x.... x ( 1-18)x ( 1-1/19 ) x ( 1 - 1/20 )
b. 3/2 x 4/3 x 5/4 x ..... x 2006/2005 x 2007/2006 x 2008/2007
giải hộ mih nhé
a)[1-1/2]x[1-1/3]x[1-1/4]x..........[1-1/18]x[1-1/19]x[1-1/20]
b)1/1/2x1/1/3x1/1/4x1/1/5........x1/1/2005x1/1/2006x1/1/2007
Tính 1/1x 2+1/2 x 3+...1/18 x 19+1/19 x 20
Tìm x
x : 1/2 + 3/4 = 1 và 19/20
x + x x 1/3 + 5/18 = 1 và 1/6
Cho mình câu trả lời nhanh nhất nhé
a)\(\left(1-\frac{1}{2}\right)x\left(1-\frac{1}{3}\right)x\left(1-\frac{1}{4}\right)x\left(1-\frac{1}{5}\right)x......x\left(1-\frac{1}{18}\right)x\left(1-\frac{1}{19}\right)x\left(1-\frac{1}{20}\right)\)
b)\(1\frac{1}{2}x1\frac{1}{3}x1\frac{1}{4}x1\frac{1}{5}x......x1\frac{1}{2005}x1\frac{1}{2006}x1\frac{1}{2007}\)
Tính
(1 + 2 + 4 +7 + 11 + ........ + 211) - ( 1 x 19 + 2 x 18 + 3,17 + 19 x 1)
làm nhanh nha
