a)\(16^x=32^8\)
\(\Rightarrow\left(2^4\right)^x=\left(2^5\right)^8\)
\(\Rightarrow2^{4x}=2^{40}\)
\(\Rightarrow4x=40\)
\(\Rightarrow x=10\)
b)\(4^x=32^{40}\)
\(\Rightarrow\left(2^2\right)^x=\left(2^5\right)^{40}\)
\(\Rightarrow2^{2x}=2^{200}\)
\(\Rightarrow2x=200\)
\(\Rightarrow x=100\)
c)\(\left(\dfrac{2}{3}\right)^x=\left(\dfrac{4}{9}\right)^4\)
\(\Rightarrow\left(\dfrac{2}{3}\right)^x=\left[\left(\dfrac{2}{3}\right)^2\right]^4\)
\(\Rightarrow\left(\dfrac{2}{3}\right)^x=\left(\dfrac{2}{3}\right)^8\)
\(\Rightarrow x=8\)
d)\(2^{3x+1}=32^2\)
\(\Rightarrow2^{3x+1}=\left(2^5\right)^2=2^{10}\)
\(\Rightarrow3x+1=10\)
\(\Rightarrow3x=9\)
\(\Rightarrow x=3\)
e)\(\left(2x-1\right)^3:7=49\)
\(\Rightarrow\left(2x-1\right)^3=343\)
\(\Rightarrow\left(2x-1\right)^3=7^3\)
\(\Rightarrow2x-1=7\)
\(\Rightarrow2x=8\)
\(\Rightarrow x=4\)
a) Ta có: \(16^x=32^8\)
=> \(\left(2^4\right)^x=\left(2^5\right)^8\)
=> \(2^{4.x}=2^{5.8}\)
=> 4x = 40
=> x = 10
Vậy x =10
b) Ta có : \(4^x=32^{40}\)
=> \(\left(2^2\right)^x=\left(2^5\right)^{40}\)
=> \(2^{2x}=2^{5.40}\)
=> 2x = 200
=> x =100
Vậy x = 100
c) Ta có : \(\left(\dfrac{2}{3}\right)^x=\left(\dfrac{4}{9}\right)^4\)
=> \(\left(\dfrac{2}{3}\right)^x=\left(\dfrac{2}{3}\right)^{2.4}\)
=> x = 8
Vậy x =8
d) Ta có : \(2^{3x+1}=32^2\)
=> \(2^{3x+1}=\left(2^5\right)^2\)
=> 3x+1 =5.2
=> 3x+1 = 10
=> 3x = 10-1=9
=> x= \(\dfrac{9}{3}\)=3
Vậy x = 3
e) (2x-1)\(^3\) : 7 = 49
(2x-1)\(^3\) = 49.7
(2x-1)\(^3\) = 343
(2x-1)\(^3\) = \(7^3\)
=> 2x-1 = 7
2x = 8
x = 8:2
x = 4
Vậy x = 4
