tham khảo
https://hoidap247.com/cau-hoi/1604273
Theo đề ta có:
a-x/b-y=a/b\(\Rightarrow\)(a-x)b=(b-y)a\(\Rightarrow\)ab-bx=ba-ya
\(\Rightarrow\)xb=ya\(\Rightarrow\)x/y=a/b(ĐPCM)
Chúc bạn học tốt
Ta có: \(\dfrac{a-x}{b-y}=\dfrac{a}{b}\)
\(\Leftrightarrow a\left(b-y\right)=b\left(a-x\right)\)
\(\Leftrightarrow ab-ay=ab-bx\)
\(\Leftrightarrow-ay=-bx\)
\(\Leftrightarrow bx=ay\)
hay \(\dfrac{x}{y}=\dfrac{a}{b}\)(đpcm)