<PRE><B>Question 713499</B>
{{{(20X+5Y)/(4.5)=10}}} AND {{{X+Y=4.5}}}


The numbers of the problem were chosen by the author so you could conveniently divide the percentage equation by 5; you should then multiply both sides by 4.5.

{{{4X+Y=45}}}


The system to solve is this:
{{{4X+Y=45}}}
{{{X+Y=4.5}}}
This is also very convenient because now you can subtract the second equation from the first equation and quickly get a value for X.  


{{{3X+0=40.5}}},.... See?  Now quickly solve for X....</PRE>