Question

tìm x biết:   ( x-1)+(x-2)+....+ (x-19)+(x-20)=610

Answer 1

( x-1)+(x-2)+....+ (x-19)+(x-20)=610.

=>(x+x+x+...x)+(1+2+3+...+20)=610

=>        20x     +          210        = 610

=>       20x                                =610-210

=>       20x                               =400 

=>          x                                =400:20

=>         x                                 = 20

Answer 2

bằng 41

Answer 3

bằng 41 nha bn

Answer 4

( x - 1 ) + ( x - 2 ) + . . . . . + ( x - 19 ) + ( x - 20 ) = 610

=> ( x + x + . . . . . + x + x ) - ( 1 + 2 + . . . . . + 19 + 20 ) = 610

=> ( x + x + . . . . . + x + x ) - \(\left\{\left[\left(20-1\right):1+1\right]\cdot\left(20+1\right)\right\}:2\) = 610

=> ( x + x + . . . . . + x + x ) - 210 = 610

=> x * 20 = 610 + 210

=> x * 20 = 820

=> x = 820 : 20

=> x = 41

Answer 5

(x-1)+.....+(x-20)=610

(x+.....+x)-(1+2+.....+20)=610

20x-210=610

20x=610-210=400

x=400:20=20

Answer 6

Ta có: (x-1)+(x-2)+(x-3)+...+(x-19)+(x-20)=610

=> (x+x+x+..+x  (20x) )-(1+2+3+...+20)=-610

=> 20x-210=-610

=> 20x=(-610)+210

=> 20x=-400

=> x=(-400):20

=> x=-20

Vậy x là -20

Answer 7

kết quả đũng là 20

Answer 8

(x - 1) + (x - 2) +.....+ (x - 19) + ( x - 20) = 610

=>(x + x + x...+ x) - (1 + 2 + 3 +...+ 20) = 610

=> 20x - 210 = 610.

=> 20x = 610+210

=> 20x = 820

=> x = 820 : 20

=> x = 41