Respuesta :

(230 + w) x ( t ) = ( 275 )
(230 - w) x ( t ) = ( 185) 

t = 275 / (230 + w)
t = 185 / (230 - w) 

275 / (230 + w) = 185 / (230 - w)
275(230 - w) = 185(230 + w)
63250 - 275w = 42550 + 185w
20700 = 460w
w = 45mph