\(\dfrac{8}{27}=\dfrac{2^n}{3\text{x}3^m}\)
=>\(\dfrac{2^3}{3^3}=\dfrac{2^n}{3\text{x}3^m}\)
n=3và \(3\text{x}3^2=3^{1+2}\)=>m=2
Vậyn=3,m=2
thuc hien phep tinh
\(\dfrac{4^3+2^5+8^5}{8^3\times3+16+3^3}\)
2) tìm số tự nhiên n biết:
\(\left(\dfrac{1}{3}\right)^n=\dfrac{1}{27};\left(\dfrac{3}{5}\right)^n=\dfrac{81}{625}\)
Nhờ mọi người giúp mình vs!
Tìm x thuộc Q khi:
a)3x-1 =243
b)\(\left(\dfrac{2}{3}\right)^{x+1}=\dfrac{8}{4}\)
c) 3x+3x+2=270
d) \(\left(x-\dfrac{5}{2}\right)^2=144\)
e) \(\left(2x+1\right)^3=\dfrac{215}{27}\)
f) (2x-1)5 = -243
h) (27-1)2 = (2x-1)2
i) (2x+1)2 + (x+1)10 = 0
k) \(\dfrac{x-2}{5}=\dfrac{X+3}{2}\)
l) \(\dfrac{2}{x}=\dfrac{x}{50}\)
m) \(\dfrac{\left(x-3\right)}{4}=\dfrac{4}{x+3}\)
n) \(|x+\dfrac{3}{5}|-|x-\dfrac{7}{3}|\)
thục hiện phép tính
A = \(\dfrac{3}{1\times5}+\dfrac{3}{5\times10}+....+\dfrac{3}{100\times105}\)
B=\(\dfrac{5}{1\times3\times5}+\dfrac{5}{3\times5\times7}+...+\dfrac{5}{99\times101\times103}\)
tìm x,y,z
\(\dfrac{x-4}{2}\)=\(\dfrac{y-6}{3}\)=\(\dfrac{z-8}{4}\) và bt x+y+z =27
(giải theo phuong phap đặt)
Bài 1: Tìm n \(\in\) Z biết:
\(e)3^{-1}.3^n+6.3^{n-1}=7.3^6\)
\(g)3^4< \dfrac{1}{9}.27^n< 3^{10}\)
\(h)25< 5^n:5< 625\)
Bài 2: Tìm x biết:
\(\dfrac{2.\left(\dfrac{-1}{2}\right).\left(\dfrac{2}{3}\right)^2-3.\left(\dfrac{-1}{2}\right)^2.\dfrac{2}{3}+1}{3.\left(\dfrac{-1}{2}\right)-\dfrac{2}{3}}\)
Help me !!!!!!!!!!!!! giúp mk vs các bn giỏi toán 
Tìm n, biết:
a) \(\dfrac{-32}{\left(-2\right)^n}=4\)
b) \(\dfrac{8}{2^n}=2\)
c) \(\dfrac{16}{\left(-2\right)^n}=-8\)
\(\dfrac{\left(x+3\right)^5}{\left(x+3\right)^2}=\dfrac{64}{27}\)
tìm x biết
a)\(\dfrac{x^7}{81}=27\)
b)\(\dfrac{x^8}{9}=729\)