Bài 2:
\(A=\sqrt{2x+5}+9>=9\)
Dấu '=' xảy ra khi x=-5/2
Bài 3: \(M=\dfrac{16^6+4^4}{16^5+16}\)
\(\Rightarrow\) \(M=\dfrac{16^6+4^4}{16^5+4^2}\) \(\Rightarrow\) \(M=\dfrac{16+4^2}{1+1}\)
\(\Rightarrow\) \(M=\dfrac{16+16}{2}\) \(\Rightarrow\) \(M=\dfrac{32}{2}=16\)