Question

[Bùi Xuân Mai]

Cho a/b = c/d. Chứng minh rằng

a) a/b=7a+5c/7b+5d ( 7b # 5d # 0 )

b) 3a^6+ c^6 / (a+c)^6 / (b+d)^6

Answer 1

[Phùng Hữu Kiên]

a) \(\frac{a}{b}=\frac{c}{d}\Rightarrow\frac{a}{b}=\frac{c}{d}=\frac{7a}{7b}=\frac{5c}{5d}\)

\(\Rightarrow\frac{a}{b}=\frac{7a+5c}{7b+5d}\)