Question 903357
{{{x+y=12000}}}
{{{0.09*x=0.11*y}}}

{{{x=12000-y}}}
{{{0.09*(12000-y)=0.11*y}}}
{{{1080-0.09*y=0.11*y}}}
{{{1080=0.11*y+0.09*y}}}
{{{1080=0.2*y}}}
{{{y=5400}}}
{{{x=12000-5400}}}
{{{x=6600}}}

Ans:$6600 and $5400