a.
(2x+1)2 = 25 = 52
=> 2x + 1 = 5
=> 2x = 4
=> x = 2
Vậy x = 2
b.
52x+1 = 125 = 53
=> 2x + 1 = 3
=> 2x = 2
=> x = 1
Vậy x = 1
Chúc em học tốt!!!
a, ( 2x + 1 )2 = 25
<=> ( 2x + 1 )2 = 52
=> 2x + 1 = 5
=> 2x = 4
=> x = 2
b 52x + 1 = 125
<=> 52x+1 = 53
=> 2x + 1 = 3
=> 2x = 2
=> x = 1
\(\left(2x+1\right)^2=25\)
\(\left(2x+1\right)^2=\left(\pm5\right)^2\)
\(\Rightarrow\orbr{\begin{cases}2x+1=5\\2x+1=-5\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=2\\x=-3\end{cases}}\)
\(5^{2x+1}=125\)
\(\Rightarrow5^{2x+1}=5^3\)
\(\Rightarrow2x+1=3\)
\(\Rightarrow x=2\)
a. \(\left(2x+1\right)^2=25\)
\(\Leftrightarrow\left(2x+1\right)^2=5^2\)
\(\Leftrightarrow2x+1=5\)
\(\Leftrightarrow2x=6\)
\(\Rightarrow x=3\)
b. \(5^{2x+1}=125\)
\(\Leftrightarrow5^{2x+1}=5^5\)
\(\Leftrightarrow2x+1=3\)
\(\Leftrightarrow2x=4\)
\(\Rightarrow x=2\)
a, ( 2x + 1 )2 = 25
<=> (2x + 1 )2 = 52
=> 2x + 1 = 5
=> 2x = 4
=> x = 4 : 2
=> x = 2
b, 52x +1 = 125
<=> 52x + 1 = 53
=> 2x + 1 = 3
=> 2x = 2
=> x = 1