Question

Từ \(\frac{a}{b}=\frac{c}{d}\) Hãy suy ra tỉ lệ thức sau : \(\frac{a+b}{b}=\frac{c+d}{d}\)

Answer 1

\(\frac{a}{b}=\frac{c}{d}\frac{a}{c}=\frac{b}{d}=>\frac{a+b}{c+d}=\frac{b}{d}=>\frac{a+b}{b}=\frac{c+d}{d}\) (hón vị trung tỉ)

nhớ liike nhé!

Answer 2

Đặt \(\frac{a}{b}\)= \(\frac{c}{d}\)= k

=> a = b.k, c = d.k

Ta có: Vế trái(VT) = \(\frac{a+b}{b}\)= \(\frac{b.k+b}{b}=\frac{b.\left(k+1\right)}{b}=k+1\)

           Vế phải(VP) = \(\frac{c+d}{d}=\frac{d.k+d}{d}=\frac{d.\left(k+1\right)}{d}=k+1\)

=> VT=VP(đpcm)