1. Cho \(\dfrac{a}{b}\) = \(\dfrac{c}{d}\) c/m

a) (2a+3c) . (2b-3d) = (2a- 3c) . (2b+3d)

b) \(\dfrac{\left(a^2+c\right)^2}{\left(b+d\right)^2}\) = \(\dfrac{\left(a-c\right)^2}{\left(b-d\right)^2}\)

c)\(\dfrac{a^3+b^3}{c^3+d^3}\) = \(\dfrac{a^3-b^3}{c^3-d^3}\)

d) \(\dfrac{a^{2018}-b^{2018}}{a^{2018}+b^{2018}}\) = \(\dfrac{c^{2018}-d^{2018}}{c^{2018}+d^{2018}}\)

HELP ME >~< !!!

1. cho \(\dfrac{a}{b}\) = \(\dfrac{d}{c}\)

a) \(\dfrac{a+b}{b}\) = \(\dfrac{c+d}{d}\)

b) \(\dfrac{a}{a-b}\) = \(\dfrac{c}{c-d}\)

c) \(\dfrac{2a-5b}{2c-5d}\) = \(\dfrac{3a+4b}{3c+4d}\)

d) \(\dfrac{a^2-c^2}{b^2-d^2}\) = \(\dfrac{ac}{bd}\)

HELP ME !!! MK SẼ TICK CHO