\(=-2018+x-2019+x-x+2018-2x+2019\)
\(=\left(-2018+2018\right)+\left(-2019+2019\right)+\left(x+x-x-2x\right)\)
\(=0+0-x\)
\(=-x\)
Các câu hỏi tương tự
Chứng minh rằng :
a) 2x + 2y / x + y = 2 ( x + y khác 0 )
b) 2018 / 2019 = 2018 . 2018 . 2018 / 2019 . 2019 . 2019
giúp mk nha mn . ai nhanh mk tick !!!
x +(x+1) + ( x+2)+...+2018+2019=2019
x+(x+1)+(x+2)+....+2018+2019=2019
X+(X+1)+(x+2)+...+2018+2019=2019
x+(x+1)+(x+2)+......+2018+2019=2019
x+(x+1)+(x+2)+...2018+2019=2019
(x-2019)2019=(x-2019)2018
Tìm x
Tìm x : x+(x+1)+(x+2)+...+2018+2019=2019
tìm x biết : x+(x+1)+(x+2)+...+2018+2019=2019