Question

magnification = f-v/f ​

Answer 1

We know,

Magnification = -v/u = (-v) x (1/u)

We know,

1/f= 1/v + 1/u

1/u= 1/f-1/v

=(v-f)/fv

Substitute 1/u in formula,

m= (-v) x (1/u)

= (-v) x (v-f)/vf

= f-v/f

Hope you have understood.