\(\dfrac{a}{b}=\dfrac{c}{d}\rightarrow\dfrac{5a^5}{5b^5}=\dfrac{c^5}{d^5}=\dfrac{5a^5+c^5}{5b^5+d^5}\)
\(\dfrac{a}{b}=\dfrac{c}{d}=\dfrac{a+c}{b+d}\)
\(\dfrac{a^5}{b^5}=\dfrac{c^5}{d^5}=\dfrac{\left(a+c\right)^5}{\left(b+d\right)^5}\)
nên ta có
\(\dfrac{5a^5+c^5}{5b^5+d^5}=\dfrac{\left(a+c\right)^5}{\left(b+d\right)^5}\)