A. 13; 44; 76
B. 40; 57; 99
C. 13; 57; 85
D. 40 ; 85; 69
\(A=\frac{1+13^4+13^8+..+13^{96}+13^{100}}{1+13^2+13^4+..+13^{98}+13^{102}}\)TÍNH A
cho A = 13+13^2+13^3+13^4+...............+13^99+13^100 . Chứng minh rằng A chia hết cho 182
A=(13+132)+(133+134)+.......................+(1399+13100)
A=1.(13+132)+132.(13+132)+..............+1398.(13+132)
A=1.182+132.182+..........................+1398.182
A+182.(1+132+..............+1398) Chia hết cho 182
--> A chia hết cho 182
Cho A= \(^{^{13+13^2+13^3+13^4+13^5+13^6}}\). Chứng tỏ rằng A chia hết cho 2
Ta có: \(A=\left(13+13^2\right)+\left(13^3+13^4\right)+\left(13^5+13^6\right)\)
\(=13\left(13+1\right)+13^3\left(13+1\right)+13^5\left(13+1\right)\)
\(=14\left(13+13^3+13^5\right)\)
\(=2.7.\left(13+13^3+13^5\right)\) chia hết cho 2
A=130+131+132+133......+1399+13100.
A=?
Xin lỗi mk viết nhầm
12A=13101-1
=>\(A=\frac{13^{101}-1}{12}\)
A=\(\dfrac{13^{15}+1}{13^{16}+1}\) và B= \(\dfrac{13^{16}+1}{13^{17}+1}\)
so sánh A và B
\(ta có A=\dfrac{13^{15}+1}{13^{16}+1}=\dfrac{13^{15}}{13^{16}}+1\)=\(\dfrac{1}{13}+1\)
B=\(\dfrac{13^{16}+1}{13^{17}+1}=\dfrac{13^{16}}{13^{17}}+1\)=\(\dfrac{1}{13}+1\)
vậy A=B
\(A=\dfrac{13^{15}+1}{13^{16}+1}vàB=\dfrac{13^{16}+1}{13^{17}+1}\)
ta có
\(\dfrac{13^{16}+1}{13^{17}+1}< 1\Rightarrow\dfrac{13^{16}+1+12}{13^{17}+1+12}=\dfrac{13\left(13^{15}+1\right)}{13\left(13^{16}+1\right)}=\dfrac{13^{15}+1}{13^{16}+1}=A\)
vậy B<A
\(A=\dfrac{13^{15}+1}{13^{16}+1}vàB=\dfrac{13^{16}+1}{13^{17}+1}\)
ta có B<1 nên
\(\dfrac{13^{16}+1}{13^{17}+1}< \dfrac{13^{16}+1+12}{13^{17}+1+12}=\dfrac{13\left(13^{15}+1\right)}{13\left(13^{16}+1\right)}=\dfrac{13^{15}+1}{13^{16}+1}=A\)
Vậy B<A
Cho A = 13 + 132 + 133 + 134 + ... + 1360 . Chứng minh rằng A chia hết cho 3 , 7 ,61
Cho A = 1315+1/1314+1
B = 1314+1/1313+1
So sánh A và B
nhân 13 với A và B
so sánh mẫu =>mẫu nào lớn hơn thì bé hơn
là xong
a) A= \(\dfrac{2}{13}\).\(\dfrac{5}{9}\)+\(\dfrac{2}{13}\).\(\dfrac{4}{9}\)+\(\dfrac{11}{13}\)
`2/13 . 5/9+ 2/13 . 4/9 +11/13`
`= 2/13 . ( 5/9 + 4/9)+11/13`
`= 2/13 . 9/9 +11/13`
`= 2/13 . 1 + 11/13`
`= 2/13 +11/13`
`=13/13`
`=1`
`@ yl`
`2/13*5/9+2/13*4/9+11/13`
`=2/13*(5/9+4/9)+11/13`
`=2/13*9/9+11/13`
`=2/13*1+11/13`
`=2/13+11/13`
`=13/13=1`
\(A=\dfrac{2}{13}\times\dfrac{5}{9}+\dfrac{2}{13}\times\dfrac{4}{9}+\dfrac{11}{13}\\ A=\dfrac{2}{13}\times\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\dfrac{11}{13}\\ A=\dfrac{2}{13}\times1+\dfrac{11}{13}\\ A=\dfrac{2}{13}+\dfrac{11}{13}\\ A=1\)
\( A=\frac{1+13+13^2+...+13^{13}}{1+13+13^2+...+13^{12}}\) và \(B=\frac{1+11+11^2+...+11^{13}}{1+11+11^2+...+11^{12}}\) chứng minh A > B
B=3a-b/2a+13 - 3b-a/2b-13 voi a-b=13, a khac -6,5 b khac 6,5 ai dung minh tick