Question

[Hội yêu Toán]

1 x 2 x 3 x ................x 2012 x 2013 - 1 x 3 x 5 x..............x 2011 x 2013 .
(Làm chi tiết nha)

Answer 1

[✓ ℍɠŞ_ŦƦùM $₦G ✓]

Ta có : 1 x 2 x 3 x ..... x 2012 x 2013 - 1 x 3 x 5 x ..... x 2011 x 2013

= (1 x 3 x 5 x ..... x 2013) x (2 x 4 x 6 x ..... x 2012) -  1 x 3 x 5 x ..... x 2011 x 2013

= (1 x 3 x 5 x ..... x 2011 x 2013) x (2 x 4 x 6 x ..... x 2012 - 1)