Answer It....!

http://umakes.com.vn/internet-technology/

7 - 4 + 0 + 1
= 7 - 5
= 2

Source: http://www.ibosocial.com/margur2000/pressrelease.aspx?prid=423203
via: http://umakes.com.vn/photo/2694/what-039-s-your-answer/