Lời giải:
\(64^x.9^2=16^x.2^{2x+9}-431\)
\(\Leftrightarrow 2^{6x}.81=2^{4x}.2^{2x+9}-431\)
\(\Leftrightarrow 2^{6x}.81=2^{6x}.2^9-431\)
\(\Leftrightarrow 2^{6x}.81=2^{6x}.512-431\)
\(\Leftrightarrow 2^{6x}(512-81)=431\)
\(\Leftrightarrow 2^{6x}.431=431\Leftrightarrow 2^{6x}=1\Rightarrow 6x=0\Rightarrow x=0\)