a) cho: \(\dfrac{a}{b}=\dfrac{c}{d}\)
và a, b, c, d \(e\) 0 ; \(2017a-2018be0;2017c-2018de0\)
CMR: \(\dfrac{2017a+2017b}{2017a-2017b}=\dfrac{2017c+2018d}{2017c-2018d}\)
b) cho \(a^2=bc\)
CMR: \(\dfrac{c}{b}=\dfrac{a^2+c^2}{b^2+a^2}\)
Loga
Toán lớp 7
