Question

Cho a/c = c/b chứng minh rằng (a²+c²) / (b²+c²) = a/b

Answer 1

\(\frac{a}{c}=\frac{c}{b}\Rightarrow c^2=ab\)

ta có: \(\frac{a^2+c^2}{b^2+c^2}=\frac{a^2+ab}{b^2+ab}=\frac{a\left(a+b\right)}{b\left(a+b\right)}=\frac{a}{b}\left(đpcm\right)\)