Question

Tìm giá trị của x :

x + ( x - 1 ) + ( x -2 ) +...+ ( x - 50 ) = 1530

 

Answer 1

x+(x-1)+(x-2)...(x-50)=1530

x+x+...+x-(1+2+...+50)=1530

50x-1275=1530

50x=2805

x=56,1

Answer 2

x + ( x - 1 ) + ( x -2 ) +...+ ( x - 50 ) = 1530

x + x . 50  - ( 1 + 2 + ... + 50 ) = 1530

x + x. 50 - 1275 = 1530

x + x. 50 = 1530 + 1275 

x + x . 50 = 2805

x . ( 50 + 1 ) = 2805

x . 51 = 2805

x = 2805 : 51

x = 55

Answer 3

x+(x-1)+(x-2)+...+(x-50)=1530
(x+x+x+...+x)-(1+2+3+...+50)=1530
51.x-1275=1530
51.x=1530+1275
51.x=2805
x=2805:51
x=55

Answer 4

x + ( x - 1 ) + ( x -2 ) +...+ ( x - 50 ) = 1530

( x + x + ....+ x ) -  ( 1 + 2 + 3 + .... + 50 ) = 1530

51 . x - 1275 = 1530

51 . x             = 1530 + 1257

51 . x             = 2805

      x              = 2805 : 51 

      x              = 55

hok tốt

Answer 5

x + ( x - 1 ) + ( x -2 ) +...+ ( x - 50 ) = 1530

 \(\Rightarrow\)         ( x + x + ....+ x ) - ( 1 + 2 + 3 + .... + 50 ) = 1530

    \(\Rightarrow\)      51 . x - 1275 = 1530

    \(\Rightarrow\)       51 . x = 1530 + 1257

    \(\Rightarrow\)        51 . x = 2805

\(\Rightarrow\)             x = 2805 : 51 

 \(\Rightarrow\)            x = 55