Question

A butterfly starts at 20m and changes -16m

Answer 1

You should use Google.

Answer 2

Answer:

Let butterfly was at point O.After some time

Position of Butterfly(OA) = 20 m

After flying through certain distance

  Butterfly moved in backward direction(AB) = -16 m

There is negative sign before number 16.It means butterfly moved in backward direction.

So, final position of butterfly

      =OA - AB

    =+20 +(-16)

     =20-16

  =4 m, from Initial position.