Câu trả lời:
1, a, \(2012.24+77.2012-2012=2012\left(24+77-1\right)=2012.100=201200\)
b, \(3^3.76+84.27+3^2.3.40=3^3.76+84.3^3+3^3.40=3^3\left(76+84+40\right)=3^3.200=5400\)
c, \(\frac{2^{83}+2^{84}+2^{85}}{2^{82}+2^{81}+2^{80}}=\frac{2^{83}\left(1+2+2^2\right)}{2^{80}\left(2^2+2+1\right)}=\frac{2^{83}}{2^{80}}=2^3=8\)
2. a, \(5^{2x+1}=125\Rightarrow5^{2x+1}=5^3\Rightarrow2x+1=3\Rightarrow x=1\)
d, \(\left(2x+3\right)^4=81\Rightarrow\left(2x+3\right)^4=3^4\Rightarrow2x+3=3;-3\)
\(\Rightarrow\orbr{\begin{cases}2x+3=3\\2x+3=-3\end{cases}\Rightarrow\orbr{\begin{cases}x=0\\x=-3\end{cases}}}\)