Question 616359
{{{20/u = 25/(u-1)}}}


{{{20(u-1) = 25u}}}


{{{20u-20 = 25u}}}


{{{-20 = 25u-20u}}}


{{{-20 = 5u}}}


{{{-20/5 = u}}}


{{{-4 = u}}}


{{{u = -4}}}



So the solution is {{{u = -4}}}