Question 789849
let the first interest is x
then the second one will be x+1

so the total interest is {{{4000x/100 + 5000(x+1)/100 = 40x + 50(x+1) = 90x+50}}}

so {{{90x + 50 = 500}}}

then {{{90x = 500-50}}}
      {{{90x = 450}}}
       {{{x = 450/90}}}
      {{{ x = 5 }}}