Question 1118391
<pre>
x    at   12%
y    at   14%
x+y  at   15%
------------------
------------------2x+2y=6000  or x+y=3000
</pre>

Yearly Income,  $840
{{{12x+14y+15(x+y)=84000}}}, and {{{x+y=3000}}}.

{{{12x+14y+15*3000=84000}}}

{{{12x+14y=84000-45000}}}

{{{12x+14y=39000}}}

{{{12x+14(3000-x)=39000}}}------from hear, the algebra is a few short simple steps....