1^3 +2^3+3^3+4^3 + .....+100^3=33996600+5050=34001650

đúng đó bạn ạ . k mình nha

A=88573

phan B to lam khoang tam 14 chu so tran man hinh mt vinacal, mik k tinh dk

Làm rõ ràng mk k cho :)

A= 3( 1+3+3^2+3^3+3^4+3^5+3^6+3^7+3^8) chia hết cho 3

\(Vào\)\(câu\)\(hỏi\)\(tương\)\(tự\)

ありがとございます

\(A=3+3^2+........+3^{60}\)

\(3A=3.\left(3+3^2+......+3^{60}\right)\)

\(3A=3^2+3^3+.....+3^{61}\)

\(3A-A=\left(3^2+3^3+.......+3^{61}\right)-\left(3+3^2+.....+3^{60}\right)\)

\(2A=3^{61}-3\)

\(A=\left(3^{61}-3\right):2\)

Ta có: A= 3+3^2+3^3+3^4+...+3^60

\(\Rightarrow\)3A= 3^2+3^3+3^4+...+3^60+3^61 

\(\Rightarrow\)3A-A= (3^2+3^3+3^4+...+3^60+3^61 )- (3+3^2+3^3+3^4+...+3^60)

\(\Rightarrow\)2A= 3^61-3

\(\Rightarrow\)A= \(\frac{3^{61}-3}{2}\)

NHớ k cho mk nhá

Gọi  \(ƯCLN\left(6n+5;3n+2\right)\) là d.

\(\Rightarrow\hept{\begin{cases}6n+5⋮d\\3n+2⋮d\end{cases}}\)

\(\Rightarrow\hept{\begin{cases}6n+5⋮d\\2\left(3n+2\right)⋮d\end{cases}}\)

\(\Rightarrow\hept{\begin{cases}6n+5⋮d\\6n+4⋮d\end{cases}}\)

\(\Rightarrow\left(6n+5\right)-\left(6n+4\right)⋮d\)

\(\Rightarrow1⋮d\)

\(\Rightarrow d=1\)

\(\Rightarrow\left(6n+5;3n+2\right)=1\)

\(\Rightarrow\frac{6n+5}{3n+2}\) tối giản.

\(\frac{6n+5}{3n+2}\)tối giản

=>6n+5 chia hết cho 3n+2 

=>(6n+5)-2(3n+2)chia hết cho 3n+2

=>6n+5-6n-4 chia hết cho 3n+2

=>1 chia hết cho 3n+2

=>đpcm

4432320

3 x 3 x 3 x 4 x 57 x 8 x 90 = 4432320