Question

Tính tổng:

2 - 4 + 6 - 8 + .... + 48 -50

Answer 1

Dat A=2-4+6-8+..+48-50

Bieu thuc A co (50-2)/2+1=26 so

Chia thanh 13 nhom ,moi nhom co 2 so 

A=(2-4)+(6-8)+...+(48-50)

             13 nhom

A=(-2)+(-2)+...+(-2)

         13 so

A=(-2)*13=-26

Vay....K CHO MINH NHE

Answer 2

2-4+ 6-8 + .....+ 48-50

= -2+ -2+ .....+ -2

= -2.23

= -46