Question

[đỗ minh anh]

1,Cho TLT a/b=c/d. Chứng Minh:

a,  a+b/b=c+d/d

b,  a-b/b=c-d/d

Answer 1

[T.Ps]

#)Giải :

a) Ta có : \(\frac{a}{b}=\frac{c}{d}\Rightarrow ad=bc\Rightarrow ad+bd=bc+bd\Rightarrow d\left(a+b\right)=b\left(c+d\right)\Rightarrow\frac{a+b}{b}=\frac{c+d}{d}\)

\(\Rightarrowđpcm\)

b) Ta có : \(\frac{a}{b}=\frac{c}{d}\Rightarrow ad=bc\Rightarrow ad-bd=bc-bd\Rightarrow d\left(a-b\right)=b\left(c-d\right)\Rightarrow\frac{a-b}{b}=\frac{c-d}{d}\)

\(\Rightarrowđpcm\)