Chứng minh a^2019 + c^2019/ b^2019 + d^2019 = (a + b)^2019/ (b + d)^2019

Cho a/b=c/d(a,b,c,d khác 0) Chứng minh a^2019+c^2019/b^2019+d^2019=(a+b)^2019/(b+d)^2019