Respuesta :

Answer:

B

Step-by-step explanation:

if you multiply m by 2 you get 260we now want to subtract this from 360 to get 100 then we divide that by 2 to get angle n∠BEF= 50°.

We know angle k∠EBF= 90° so we now end up with adding angle ∠BEF with ∠EBF  to get 140 to get angle x we subtract 140 from 180 to get 40. x=40°. so B is the correct answer