1+2-3-4+5+6-7-8+9+10-11-12+........+298-299-300+301+302 = 

1+2+(5-3)+(6-4)+(9-7)+(10-8)+…….+(301-299)+(302-300)=

Từ 302 đến 3 có số cặp là [(302-3):1+1]:2=150 cặp. Mà mỗi cặp có giá trị là 2

Vậy 1+2-3-4+5+6-7-8+9+10-11-12+........+298-299-300+301+302 = 

1+2+2×150=3+300=303

303 ok

Ta chia thành: 1 + (2-3-4+5) + (6-7-8+9)+....+(298-299-300+301) + 302 = 1 + 0 + 0 + 0 + .....+ 0 + 302 = 1+302 = 303

303 bạn nhé

1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + 9 + 10 - 11 - 12 +........- 299 -300 + 301 +302

Theo đề ta có:

Cho A= 1 + 2 - 3 - 4 + 5 + 6 - 7 - 8 + 9 + 10 - 11 - 12 +........- 299 -300 + 301 +302

=> 1 + (2 - 3 - 4 + 5 )+ (6 - 7 - 8 + 9) + (10 - 11 - 12 +13)........(289- 299 -300 + 301) +302

=> 1+ 0+ 0+.....+ 0+ 302

=> 1+302

=> 303

Ta chia thành: 1 + (2-3-4+5) + (6-7-8+9)+....+(298-299-300+301) + 302 = 1 + 0 + 0 + 0 + .....+ 0 + 302 = 1+302 = 303

**** cho mk nha bạn !!!
 

1+2-3-4+5+6-7-8+9+10-11-12+.....-299-300+301+302
=1+(2-3)+(-4+5)+(6-7)+(-8+9)+(10-11)+... +(-300+301)+302
= 1-1+1-1+1-1+...-1+302
= 302

Học tốt

@Trung

302 nha bạn hok tốt

1+2-3-4+5+6-7-8+9+10-11-12+...+299-300+301+302

=1+(2-3-4+5)+(6-7-8+9)+(10-11-12+13)+...+(298-299-300+301)+302

=1+0+0+0+...+0+302

=1+302

=303

1+2-3-4+5+6-7-8+9+10-11-12+...-299-300+301+302

=(1+2-3)+(4+5+6-7)+...+(298-299-300+301)+302

=   0      +    0         +...+     0                    + 302

=302

 1+2-3-4+5+6-7-8+9+10-11-12+13...............-299-300+301+302
= 1 + (2-3-4+5)+(6-7-8+9) + (10-11-12+13)+.......................+(298-299-300+301)+302
= 1 + 0 + 0 + 0 + .......................+ 0 + 302
=  303

 

1+2-3-4+5+6-7-8+9+10-11-12+..........-299-300+301+302

= ( 1 + 2 - 3 ) - ( 4 + 4 + 6 - 7 ) + ............ - ( 299 - 300 + 301 ) + 302

= 0 - 0 + ............. - 0 + 302

= 302

nhớ ủng hộ mik nha mn

1+2‐3‐4+5+6‐7‐8+9+10‐11‐12+...‐229‐300+301+302

= (1+2‐3)+(4+5+6‐70)+...+(228‐229‐300+301)+302

= 0 + 0 +...+ 0 + 302 = 302

B = 1+2-3-4+5+6-7-8+9+10-11-12+..........-299-300+301+302

B = 1+(2-3-4+5)+(6-7-8+9)+.......+(298-299-300+301)+302

B = 1+0+0+....+0+302

B = 1+302

B = 303

303 hay 302