Question

please answer this question ​

Answer 1

Answer:

here is your answer. i know how to solve it but it will be much better for you i think

Answer 2

Answer:

hope it helps u

Step-by-step explanation:

let BQ be a and QD be b.  In triangle ABD, PQ||AB, by basic proportionality theorem,

                                             =>PQ/AB=QD/BD i.e. z/x=b/(a+b)-------i

                And, in triangle BCD, PQ||CD, by basic proportionality theorem,

                             PQ/CD i.e. z/y=a/(a+b)--------ii

                  hence, on adding i and ii

                 (z/x)+(z/y)=b/(a+b)+ a/(a+b)

             =>z(1/x + 1/y)=a+b / a+b

             =>1/x + 1/y = 1/z