Đáp án:
\(x = 0;\,\,\,y = 3\,\)
Giải thích các bước giải:
\[\begin{array}{l}
{2^x} + 124 = {5^y}\\
+ )\,\,Xet\,\,x = 0 \Rightarrow VT = {2^0} + 124 = 125\\
\Rightarrow {5^y} = 125 \Rightarrow y = 3.\\
\Rightarrow x = 0;\,\,\,y = 3\,\,\,thoa\,\,man.\\
+ )\,\,\,Xet\,\,\,x \ge 1\\
Ta\,\,co:\,\,\,{2^x}\,\,\,luon\,\,la\,\,\,so\,\,chan\\
\Rightarrow {2^x} + 124\,\,\,luon\,\,\,la\,\,\,so\,\,chan.\\
Ma\,\,\,{5^y}\,\,\,luon\,\,\,la\,\,so\,\,le\\
\Rightarrow {2^x} + 124 = {5^y}\,\,\,\,vo\,\,\,nghiem
\end{array}\]