Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
P = 1 + 5 + 52 + 53 + 54 + ..... + 52016 + 52017
= ( 1 + 5 ) + ( 52 + 53 ) + ..... + ( 52016 + 52017 )
= 6 + 52 . ( 1 + 5 ) + ..... + 52016 . ( 1 + 5 )
= 6.1 + 52 . 6 + .... + 52016 . 6 \(⋮\)6
Vậy P \(⋮\)6
Ta có:
\(P=1+5+5^2+5^3+5^4+...+5^{2016}+5^{2017}\)
\(P=\left(1+5\right)+\left(5^2+5^3\right)+...+\left(5^{2016}+5^{2017}\right)\)
\(P=1\cdot\left(1+5\right)+5^2\cdot\left(1+5\right)+...+5^{2016}\cdot\left(1+5\right)\)
\(P=1\cdot6+5^2\cdot6+...+5^{2016}\cdot6\\ ⋮6\)
Suy ra \(P⋮6\)
Vậy \(P⋮6\)
hộ mk nha bn
@@@@@@@@@@
S=5+5^2+5^3+5^4+5^5+5^6+...+5^2004
=(5+5^2+5^3+5^4)+(5^5+5^6+5^7+5^8)+...+(5^2001+5^2002+5^2003+5^2004)
=780+5^4(5+5^2+5^3+5^4)+...+5^2000(5+5^2+5^3+5^4)
=780(1+5^4+...+5^2000) chia hết cho 65
S=5+5^2+5^3+5^4+5^5+5^6+...+5^2004
=(5+5^2+5^3+5^4+5^5+5^6)+...+(5^1999+5^2000+5^2001+5^2002+5^2003+5^2004)
=19530+...+5^1998(5+5^2+5^3+5^4+5^5+5^6)
=19530(1+...+5^1998) chia hết cho 126
\(S=5+5^2+5^3+5^4+...+5^{2016}\)
\(=\left(5+5^2+5^3+5^4\right)+\left(5^5+5^6+5^7+5^8\right)+...+\left(5^{2013}+5^{2014}+5^{2015}+5^{2016}\right)\)
\(=\left(5+5^2+5^3+5^4\right)+5^4\left(5+5^2+5^3+5^4\right)+...+5^{2012}\left(5+5^2+5^3+5^4\right)\)
\(=780\left(1+5^4+...+5^{2012}\right)\)chia hết cho \(65\).
\(c,\text{Đ}\text{ặt}:A=5+5^2+5^3+...+5^{96}\)
\(A=\left(5+5^2+5^3\right)+....+\left(5^{94}+5^{95}+5^{96}\right)\)
\(A=5\left(1+5+5^2\right)+...+5^{94}\left(1+5+5^2\right)\)
\(A=5.126+...+5^{94}.126\)
\(A=126\left(5+5^4+...+5^{94}\right)\)
\(M\text{à}:A=126\left(5+5^4+...+5^{94}\right)⋮126\)
\(\Rightarrow5+5^2+5^3+...+5^{96}⋮126\)
Ra A= 5^11-5^3
Vì 5^11chia hết 125
5^3 chia hết cho125
=> 5^11-5^3 chia hết cho125
=(5+5^2+5^3+5^4+5^5)+...+(5^2012+5^2013+5^2014+5^2015+5^2016)
=126(5+5^2+5^3)+...+126(5^2012+5^2013+5^2014)
=126(5+5^2+...+5^2014)
suy ra , chia hết cho 126