Question

2006^2 - 2005^2 + 2004^2 - 2003^2 + .....+ 2^2 - 1^2

Answer 1

\(2006^2-2005^2+2004^2-2003^3+...+2^2-1^2\)

\(=\left(2006-2005\right).\left(2006+2005\right)+\left(2004-2003\right).\left(2004+2003\right)+...+\left(2-1\right).\left(2+1\right)\)

\(=2006+2005+2004+...+2+1\)

\(=\left(2006+1\right)+\left(2005+2\right)+...\left(1003+1004\right)\)

\(=2007.1003\)

\(=....\)

~ hok tốt ~

Answer 2

@Phan thi hong nhung, sao từ bước thứ 2 ra đc bước thứ 3 vậy