Đáp án:
Bạn tham khảo nhé!
Giải thích các bước giải:
\(\begin{array}{l}
\frac{a}{b} = \frac{d}{a} \Rightarrow \frac{{{a^2}}}{{{b^2}}} = \frac{{{d^2}}}{{{a^2}}}\\
Ap\,\,dung\,tinh\,\,chat\,\,day\,\,ti\,\,so\,\,bang\,\,nhau\,\,ta\,\,co:\\
\frac{{{a^2}}}{{{b^2}}} = \frac{{{d^2}}}{{{a^2}}} = \frac{{{a^2} - {b^2}}}{{{d^2} - {a^2}}}\\
\frac{a}{b} = \frac{d}{a} \Rightarrow {a^2} = bd\\
\Rightarrow \frac{{{a^2}}}{{{b^2}}} = \frac{{{d^2}}}{{{a^2}}} = \frac{{{a^2} - {b^2}}}{{{d^2} - {a^2}}} = \frac{{bd - {b^2}}}{{{d^2} - bd}}\\
\Rightarrow \frac{{{a^2} - {b^2}}}{{{d^2} - {a^2}}} = \frac{{b\left( {d - b} \right)}}{{d\left( {d - b} \right)}} = \frac{b}{d}\,\,\,\left( {dpcm} \right).
\end{array}\)
