i think x. plz explain question

Log in to add a comment

i think x. plz explain question

Log in to add a comment

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.

Draw a horizontal line at E. then:

==> BF/BD = EF/CD

==> BF = ( EF/CD) x BD ---(1)

Triangles DFE and DBA are similar.

==> FD/BD = EF/AB

==> FD = (EF/AB) x BD ----(2)

Adding (1) and (2),

BF + FD = ( EF/CD) x BD + (EF/AB) x BD = EFxBD[(1/CD) + (1/AB)

As BF + FD = BD, above can be written as

BD = EFxBD[(1/CD) + (1/AB)

Dividing both sides by BD,

1 = EFx( 1/y + 1/x) = EFx [(x + y)/xy]

==> EF = xy / (x + y)