\(\dfrac{x^7}{81}=27\\ \Leftrightarrow x^7=27\cdot81\\ \Leftrightarrow x^7=3^3\cdot3^4\\ \Leftrightarrow x^7=3^7\\ \Leftrightarrow x=3\)
Vậy \(x=3\)
\(\dfrac{x^7}{81}=27\Rightarrow x^7=27\cdot81=2187\Rightarrow x^7=3^7\Rightarrow x=3\)
Vậy x = 3
Tuyển Cộng tác viên Hoc24 nhiệm kì 26 tại đây: https://forms.gle/dK3zGK3LHFrgvTkJ6
\(\dfrac{x^7}{81}=27\\ \Leftrightarrow x^7=27\cdot81\\ \Leftrightarrow x^7=3^3\cdot3^4\\ \Leftrightarrow x^7=3^7\\ \Leftrightarrow x=3\)
Vậy \(x=3\)
\(\dfrac{x^7}{81}=27\Rightarrow x^7=27\cdot81=2187\Rightarrow x^7=3^7\Rightarrow x=3\)
Vậy x = 3
Tìm x biết:
a) \(\dfrac{-32}{\left(-2\right)^x}=4\) f) \(\left(3x-1\right)^3=\dfrac{-8}{27}\)
b) \(\left(\dfrac{1}{2}\right)^{2x-1}=\dfrac{1}{8}\) g) \(\left(2x+3\right)^2=\dfrac{9}{121}\)
c) \(\dfrac{1}{9}.27^x=3^x\) h) \(5^x+5^{x+2}=650\)
d) \(9^x:3^3=\dfrac{1}{243}\) i) \(\left(x-7\right)^{x+1}-\left(x-7\right)=0\)
e) \(\dfrac{x7}{81}=27\) m) \(\left(\dfrac{-3}{4}\right)^{3x-1}=\dfrac{256}{81}\)
x8/81=27
Tìm số tư nhiên n biết
27^n.9^n=9^27:81
1)\(\dfrac{27^4.4^3}{9^5.8^2}\)
2)\(\dfrac{8^5.3^{15}}{2^{14}.81^4}\)
CMR: 817-279+913 chia hết cho 567
27* : 3* = 9
81 : (-3)* = -243
1/2 × 2* + 4 × 2* = 9× 2^5
Tìm * ???
tìm x :
a) 72+x+2*7x-1=345
b) 81-2x*27x=95
cmr
81^7 - 27^9 - 9^13\(⋮\) 15
24^54 . 54^24 . 2^10\(⋮\) 72^63
Cho . Khi đó f(-1) bằng:
A.– 24
B.26
C.– 25
D.– 23