Question

Bài 1 : Tìm x,y thuộc Z sao cho: 

a) ( x + 1 ) + ( x + 3 ) + ( x + 5 ) + .... + ( x + 99 ) = 0 

b) \(|x-8|+|y+2|=2\)

c) x + ( x + 1 ) + ( x + 2 ) +....+ 2003 = 2003

Answer 1

\(x+\left(x+1\right)+....+2003=2003\Leftrightarrow x+\left(x+1\right)+....+2002=0\)

\(\Leftrightarrow\left(2002+x\right)\left(2002-x+1\right)=0\Leftrightarrow\left(2002+x\right)\left(2003-x\right)=0\Leftrightarrow\orbr{\begin{cases}x=-2002\\x=2003\end{cases}}\)

Answer 2

\(\left(x+1\right)+\left(x+3\right)+.....+\left(x+99\right)=0\)

\(\Leftrightarrow45x+\left(1+3+...+99\right)=0\Leftrightarrow45x+\frac{100.45}{2}=0\Leftrightarrow x+50=0\Leftrightarrow x=-50\)

Answer 3

Trl

-Bạn kia  làm đúng r nhé !~ :>

Học tốt 

nhé bạn ~