Question

Tìm X biết

a)2^2.x-5=32

b)4^2x-1=64

c)(2.X+2)²=121

d)2^x3-1=255

mn ơi giúp mik với mik cần gấp 

 

Answer 1

\(a,\Rightarrow2^{2x-5}=2^5\Rightarrow2x-5=5\Rightarrow x=5\\ b,\Rightarrow4^{2x-1}=4^3\Rightarrow2x-1=3\Rightarrow x=2\\ c,\Rightarrow\left[{}\begin{matrix}2x+2=11\\2x+2=-11\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{9}{2}\\x=-\dfrac{13}{2}\end{matrix}\right.\\ d,\Rightarrow2^{x^3}=256=2^8\Rightarrow x^3=8\Rightarrow x=2\)

Answer 2

a)
\(2^{2x-5}=2^5\)
2x-5=5
2x=10
x=5
b)
\(4^{2x-1}=4^3\)
2x-1=3
2x=4
x=2
c)
\(\left(2x+2\right)^2=11^2\)
2x+2=11
2x=9
x=9/2
 

Answer 3

a) \(2^{2x-5}=32\)

⇒\(2^{2x-5}=2^5\)

⇒\(2x-5=5\)

⇒\(2x=10\)

⇒\(x=5\)

Answer 4

d)
2^x3-1=255
2^x3=256
2^x3=2⁸
x³=8
x=2