Question

Tìm STN n biết :

1+2+3+4+...+n=465

LÀM CẢ BÀI GIẢI NHÉ

Answer 1

\(1+2+3+4+...+n=465\)

=> \(\frac{\left(n+1\right).n}{2}=465\)

=> \(\left(n+1\right).n=465.2\)

=> \(\left(n+1\right).n=930\)

=> \(\left(n+1\right).n=31.30\)

=> \(\left(n+1\right).n=\left(30+1\right).30\)

=> n = 30

Answer 2

=>(n+1).[(n-1)/1+1]/2=465

=>(n+1)n=930

=>(n+1)n=30.31

=>n=30

Answer 3

n = 30

tick nha le thi phuong

Answer 4

no lam ca bai 

30