Question

tìm x biết  

(x+1)+(x+2)+(x+3)+...+(x+20)=250

x=?

nhanh trả lời thì tui tick

 

Answer 1

\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)+...+\left(x+20\right)=250\) 

\(\Rightarrow20x+\left(1+2+3+...+20\right)=250\)

\(\Rightarrow20x+210=250\)

\(20x=250-210=40\)

\(x=40:20=2\)

\(x=2\)

Answer 2

(x+1)+(x+2)+(x+3)+...+(x+20)=250

(x+x+x+...+x)+(1+2+3+...+20)=250

20x + 210=250

20x = 250-210

20x = 40

x = 40 : 20

x = 2

Answer 3

tổng các số từ 1  - 20 :

 ( 20 + 1 ) x 20 : 2 = 210 

mà có 20 x

vậy x = 

( 250 - 210 ) : 20  = 2 

nhé !

 Đ/s : x=2

Answer 4

\(\left(x+1\right)+\left(x+2\right)+\left(x+3\right)+...+\left(x+20\right)=250\)

\(=20.x+\left(1+2+3+...+20\right)=250\)

\(=20.x+21.10=250\)

\(20.x+210=250\)
\(20.x=250-210\)

\(20.x=40\)

\(x=40:20\)

\(x=2\)