Question

The English one
Please answer

Answer 1

f = -30cm

u = -45cm

mirror formula

1/v +1/u = 1/f

1/v = 1/f -1/u

-1/30 + 1/45

(-3 + 2)/90

-1/90

v = -90cm

-v/u = h'/h

-90/45 = h'/6

-2*6 = h'

h' = -12 cm