Bài 1 : Cho \(\dfrac{a}{b}=\dfrac{c}{d}\). Chứng Minh :
a) \(\dfrac{2a+c}{2b+d}=\dfrac{a-c}{b-d}\)
b) \(\dfrac{a^2}{b^2}=\dfrac{ac+c^2}{bd+d^2}\)
c) \(\dfrac{a+3c}{b+3d}=\dfrac{a-c}{b-d}\)
d) \(\dfrac{2a-3c}{2b-3d}=\dfrac{a}{b}\)
e) \(\dfrac{a+3b}{c+3d}=\dfrac{b}{d}\)
Loga
Toán lớp 6
