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Bài 7:
a)
\(5.2^2+\left(x+3\right)=5^2\\ \Rightarrow5.4+x+3=25\\ \Rightarrow20+x+3-25=0\\ \Rightarrow x-2=0\\ \Rightarrow x=2\)
b)
\(2^3+\left(x-3^2\right)=5^3-4^3\\ \Rightarrow8+x-9=125-64\\ \Rightarrow x-1=61\\ \Rightarrow x=62\)
c)
\(4\left(x-5\right)-2^3=2^4.3\\ \Rightarrow4\left(x-5\right)-8=16.3=48\\ \Rightarrow4\left(x-5\right)=48+8=56\\ \Rightarrow x-5=\dfrac{56}{4}=14\\ \Rightarrow x=19\)
d)
\(5\left(x+7\right)-10=2^3.5\\ \Rightarrow5\left(x+7\right)-10=8.5=40\\ \Rightarrow5\left(x+7\right)=50\\ \Rightarrow x+7=\dfrac{50}{5}=10\\ \Rightarrow x=3\)
3:
a: \(2^x+2^{x+3}=144\)
=>\(2^x+8\cdot2^x=144\)
=>\(2^x=16\)
=>x=4
b: \(\left(x-5\right)^{2022}=\left(x-5\right)^{2021}\)
=>\(\left(x-5\right)^{2021}\left[\left(x-5\right)-1\right]=0\)
=>\(\left(x-5\right)^{2021}\cdot\left(x-6\right)=0\)
=>x=5 hoặc x=6
c: \(\Leftrightarrow\left(2x+1\right)^3=9\cdot9^2=9^3\)
=>2x+1=9
=>2x=8
=>x=4
a: 2x+2x+3=1442�+2�+3=144
=>2x+8⋅2x=1442�+8⋅2�=144
=>2x=162�=16
=>x=4
b: (x−5)2022=(x−5)2021(�−5)2022=(�−5)2021
=>(x−5)2021[(x−5)−1]=0(�−5)2021[(�−5)−1]=0
=>(x−5)2021⋅(x−6)=0(�−5)2021⋅(�−6)=0
=>x=5 hoặc x=6
c: ⇔(2x+1)3=9⋅92=93⇔(2�+1)3=9⋅92=93
=>2x+1=9
=>2x=8
=>x=4
