Question

solve by 1/u=1/f - 1/v where f= -2/3 and v= -5u​

Answer 1

Answer:

1/u =-3/2 - (-1/5u)

1/u=-3/2+1/5u

1/u -1/5u. =-3/2

5-1 /5u=-3/2

4/5u=-3/2

cross. multiply

==)8=-15u

=)u=-8 /15