\(2^{n+1}=2^n\cdot2^1=2^n\cdot2\)
\(2^{n+1}=2^n\cdot2^1=2^n\cdot2\)
tim n biet :
a) 2 mu n = 2 b) am 3 mu n chia 8 mu 1 c) 8 mu n chia 2 mu n =4
chung to rang 1 tren 1 mu 2 + 1 tren 1 mu 3+...+1 tren n mu 2( voi n thuoc N sao) ko phai la mot so tu nhien
a, (1/2)mu x =64
b, x mu 3 +27 =0
c, 3 mu 2 /2 mu n =4
d, 625 / 5 mu n = 5
e, 27 mu n . 3 mu n = 3 mu 2
so sanh
a, 3 mu 200 va 2 mu 300
b, 2 mu 225 va 3 mu 150
5 mu n nhan 5 mu n cong 1 nhan 5 mu n cong 2 be hon hoac bang 10 mu 18
1) tim x thuoc n biet:
a) 3 mu 4 - x = 81
b) 5 mu x -1 = 125
c) (2 - x) mu 3=27 mu 0
d)3 mu x + 2 -3 mu x +1=182
e) 2 mu x -1 -2 mu x =16
1.tim x thuoc n biet:
a)3 mu x .3 b)x mu 20 = x c)2 mu x.16 mu 2=1024 d)64.4 mu x=16 mu 8
2.tim n thuoc n sao:
a)3 mu 2.3 mu n=3 mu 5 b)(2 mu 2:4).2mu n=4 c)32<2 mu n<128 d)2.16>_2 mu n>4
ai giai dung va nhanh minh tick cho
viet tong sau thanh binh phuong cua mot so tu nhien , n lon hon hoac bang 1
1 mu 8 + 2 mu 8 + 3 mu 8 ......... n mu 8
cho n>2 , 2 mu n -1 nguyen to
c/m 2 mu n +1 la hop so
tim so tu nhien n,biet: a) (2mu n+1)=27 b) (n-2)mu 2=(n-2)mu 4 c)3 mu n+1=81 d)2mu2n+1=512
bai1
5mu3+3mu5
bai2
(x-1)mu3=125
720/(41-(2*x-5))=2mu 3*5
bai3
1 phan 9 * 3 mu 4 * 3 mu n =3 mu 7
(2 mu 2 chia 4)* 2 mu n = 4
bai4
2 * 2mu2 * 2mu3 * 2mu4 *.......*2 mu100