Question

[NiNi love bebi Thảo My nhìu]

Cho \(\frac{a}{b}=\frac{c}{d}CM\)

\(\frac{a-c}{a+c}=\frac{b-d}{b+d}\)

Answer 1

[Đinh Tuấn Việt]

Đặt \(\frac{a}{b}=\frac{c}{d}=k\) => a = bk ; c = dk

Ta có :

\(\frac{a-c}{a+c}=\frac{bk-dk}{bk+dk}=\frac{k.\left(b-d\right)}{k\left(b+d\right)}=\frac{b-d}{b+d}\)

Vậy \(\frac{a-c}{a+b}=\frac{b-d}{b+d}\)