Đáp án:
$\begin{array}{l}
A{H^2} + B{M^2} = A{N^2} + H{B^2}\\
\Rightarrow A{H^2} - A{M^2} = H{B^2} - B{M^2}\\
\Rightarrow M{H^2} = M{H^2}\\
Theo\,Pytago\left( {do:\Delta AMH \bot H;\Delta BMH \bot } \right)\\
Vậy\,A{H^2} + B{M^2} = A{N^2} + H{B^2}
\end{array}$