\(3^2.3^5.3^n=3^{11}\)
\(\Rightarrow3^7.3^n=3^{11}\)
\(\Rightarrow3^n=3^{11}:3^7\)
\(\Rightarrow3^n=3^4\)
\(\Rightarrow n=4\)
tíc mình nha
bai 1:tim x
a) (x+1/5)2+17/25=26/25
b)-1va 5/27-(3x-7/9)3=-24/27
bai 2:cho A=n+2/n-5 (n thuoc Z ;n khac 5).Tim x de A thuoc Z
tim x thuoc N biet
a, 125.n=5^7
b, 2^3.n-3^4=2^5-5
c, (2^3+2) n+3^2.n.5-10=10^2
d, 5^n.5=125
e, 9 be hon hoac bang 3^n<90
f, (3n+1)^3=64
tim x thuoc N biet
a, 125.n=5^7
b, 2^3.n-3^4=2^5-5
c, (2^3+2) n+3^2.n.5-10=10^2
d, 5^n.5=125
e, 9 be hon hoac bang 3^n<90
f, (3n+1)^3=64
tim n E N;
A, 2 mu 2 =32
27. 3 mu n= 243
64. 4mu n=4 mu 5
9 mu 2.3 mu n=3 mu 7
tim x biet
a)50<2^n<100
b)50<7^n<2500
2)a)3^n=27:5^n=625:12^n=144
b)2^n=16=128:3^n:9=27
c)(2^n+1)^3=27
TÌM n THUỘC N*
\(\frac{1}{9}.27^n=3^n\)
\(\frac{1}{2}.2^n+4.2^n=9.5^n\)
SO SÁNH
\(A=\frac{1+5+5^2+...+5^9}{1+5+5^2+...+5^9}\)VÀ \(B=\frac{1+3+3^2+...+3^9}{1+3+3^2+...+3^9}\)
tim x thuoc n: 34.3^n :9=37
tim x thuoc n: 9<3^n<27
Tim chu so tan cung cua 360
hãy so sánh a=1+3+3^2+3^3+3^4+35+36 và B=37-1
Tìm số tự nhiên x,biết :
1/x^n=1(n e N *)
2/x^n=0(n eN *)
3/x ^n=1(n e N*)
4/x^n=9
5/3^x=9
6/x^4=1
7/5^x=25
8/5^x=125
9/2^x=4
10/2^x=8
11/2^x=16
12/2^x=2^2
13/2^x=1
14/3^x=81
15/3^x=27
16/3^0=x
17/x=7^0
18/x^5=32
19/x^3=27
20/4^x=64
Chứng minh
a, 5^5 - 5^4 + 5^3 chia hết cho 7
b, 81^7 - 27^9 - 9^13 chia hết cho 45
c, 3^n+3 + 3^n+1 + 2^n+3 + 2^n+2 chia hết cho 6
