=\(\frac{1}{2}x\frac{2}{3}x\frac{3}{4}x...x\frac{2013}{2014}x\frac{2014}{2015}\)
=\(\frac{1x2x3x...x2013x2014}{2x3x4x...x2014x2015}\)
=\(\frac{1}{2015}\)
( Dau x la dau nhan)
\(=\frac{1}{2}\times\frac{2}{3}\times\frac{3}{4}\times....\times\frac{2013}{2014}\times\frac{2014}{2015}\)
\(=\frac{1}{2015}\)
Ủng hộ nhé
=1/2*2/3*3/4*...*2013/2014*2014/2015
=1/2015
=1/2x2/3x3/4x5/6.....x2013/2014x2014/2015
ta giản ước thành 1/2015
1/2x2/3x3/4x...x2014/2015
Rút gọn phân số rồi ta có:
1-1/2015=2014/2015
= 1/2 x 2/3 x 3/4 x ... x 2013/2014 x 2014/2015
= 1 x 2 x 3 x ... x 2013 x 2014 / 2 x 3 x 4 x ... x 2014 x 2015
Rút gọn ta được 1/2015
Nhớ k nha
= 1/2*2/3*3/4*.....*2013/2014*2014/2015
=1*2*3*4*...2013*2014./2*3*4*....2015
=1/2015
Ủng hộ mik nhé:)
A=(1/2 *2/3 *3/4...*2014/2015)* x^2014
A= 1/2015 * x^2014
=\(\frac{1}{2}x\frac{2}{3}x\frac{3}{4}x...x\frac{2013}{2014}x\frac{2014}{2015}\)
=\(\frac{1x2x3x...x2013x2014}{2x3x4x...x2014x2015}\)
=\(\frac{1}{2015}\)
Dau x la dau nhan
bài giải
ta rut gọn lam ra gach cac so giong nhau ket qua la 1/2015
chấc chắn luôn
\(\left(1-\frac{1}{2}\right)x\left(1-\frac{1}{3}\right)x\left(1-\frac{1}{4}\right)x.....x\left(1-\frac{1}{2014}\right)x\left(1-\frac{1}{2015}\right)\).
= \(\frac{1}{2}x\frac{2}{3}x\frac{3}{4}x......x\frac{2013}{2014}x\frac{2014}{2015}\)
= 1 x \(\frac{1}{2015}\)
= \(\frac{1}{2015}\)
1/2*2/3*3/4*...*2013/2014*2014/2015=>1/2015
