Question

[Nguyễn Thị Anh Thư]

Bai 1

 ( 1/2 - 1 ) . (1/3-  1) . ( 1/4 - 1 )....( 1/2012 - 1 ) . ( 1/2013 - 1)

Bai 2 Tim tap hop cac so nguyen x thoa man cac dieu kien sau

a) 7/2 . 5/12 - 1 < x < 23/3 ÷ 7/3 + 5/7

b) -2240/6 x + 3 ÷ 5/3 la so nguyen

Answer 1

[Jennie Kim]

\(A=\left(\frac{1}{2}-1\right)\left(\frac{1}{3}-1\right)\left(\frac{1}{4}-1\right)...\left(\frac{1}{2013}-1\right)\)

\(-A=\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)\left(1-\frac{1}{4}\right)...\left(1-\frac{1}{2013}\right)\)

\(-A=\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot...\cdot\frac{2012}{2013}\)

\(-A=\frac{1}{2013}\)

\(A=\frac{-1}{2013}\)

Answer 2

[Nguyễn Thị Anh Thư]

Con bai 2 dau ban