Question 121160
{{{1/f=1/a+1/i}}}


{{{1/f - 1/a = 1/i}}}

{{{(a - f)/af = 1/i}}}

{{{i(a - f) = af}}}

{{{i = af/(a - f)}}}


{{{i = 2000000 mm*250mm/(2000000 mm - 250mm)}}}



{{{i =  (500000000 mm^2) / (1999750 mm) }}}

{{{i =  (500000000 mm) / (1999750) }}}

{{{i =  250.03mm }}}

{{{i =  250mm }}}


Or

{{{1/f=1/a+1/i}}}


{{{1/250mm =1/2000000 mm +1/i}}}

{{{0.004mm =0.0000005mm +1/i}}}

{{{0.0040005mm =1/i}}}


{{{i =1/0.0040005mm }}}

{{{i =1/0.0040005mm }}}


{{{i =249.968mm}}}

{{{i =250mm}}}