Question

Tính:\(A=1.2.3+2.3.4+3.4.5+...+98.99.100\)

Answer 1

[1.2.3+98.99.100]x2+1=bạn tự tính nha
 

Answer 2

đây là bài lớp 5
 

Answer 3

OH MY GOD ! Bam may tinh moi het ca tay

Answer 4

25497450

tick nha bai nay minh lam roi

Answer 5

A=1.2.3+2.3.4+3.4.5+....+98.99.100

=>4A=1.2.3.4+2.3.4.4+3.4.5.4+....+98.99.100.4

=1.2.3.(4-0)+2.3.4.(5-1)+3.4.5.(6-2)+....+98.99.100.(101-97)

=1.2.3.4-0.1.2.3.+2.3.4.5-1.2.3.4+3.4.5.6-2.3.4.5+....+98.99.100.101-97.98.99.100

=98.99.100.101-0.1.2.3

=97990200

=>A=97990200:4=24497550