Question

[Chu Nguyên Bảo]

Giúp mình với, mình đang cần gấp!!!!

Answer 1

[VuongTung10x]

a, \(\frac{a}{b}=\frac{c}{d}=k\)

\(\frac{a}{b}=k\Rightarrow a=b\cdot k\)

\(\frac{c}{d}=k\Rightarrow c=d\cdot k\)

Theo bài ra ta có :

\(\frac{a+b}{b}=\frac{b\cdot k+b}{b}=\frac{b\cdot\left(k+1\right)}{v}=k+1\left(1\right)\)

\(\frac{c+d}{d}=\frac{d\cdot k+d}{d}=\frac{d\left(k+1\right)}{d}=k+1\left(2\right)\)

Từ (1) và (2) ta có

\(k+1=k+1\)

\(\Rightarrow\frac{a+b}{b}=\frac{c+d}{d}\left(đpcm\right)\)

Answer 2

[VuongTung10x]

b, Vì \(\frac{a}{b}=\frac{c}{d}\)nên :

\(\frac{a}{b}=\frac{c}{d}=\frac{3a}{3b}=\frac{2c}{2d}\)

\(\frac{a}{b}=\frac{c}{d}=-\frac{5a}{-5b}=\frac{3c}{3d}\)

\(\Rightarrow\frac{3a+2c}{3b+2d}=\frac{-5a+3c}{-5b+3d}\)