Question 1062809

The variable is the score on the final, let's call it x.

{{{ (0.15)(100) + (0.20)(99+100+97) + (0.25)x  >= 90 }}} 
{{{  15 + 59.2 + 0.25x >= 90 }}}
{{{   74.2 + 0.25x >= 90 }}}
{{{    0.25x >= 15.8 }}}
{{{   highlight(       x >= 63.2 )}}}