Question 120538
Set it up as two equations and two unknowns. Let x be the amount invested at 9%, and let y be the amount invested at 11%. Then you can write:
Eqn #1: {{{x+y=6000}}}
Eqn #2: {{{x(0.09)+y(0.11)=624}}}
=================================
Now you have 2 equations and 2 unknowns. Any time you have at least as many equations as you have unknowns, you can solve the problem!
Solve Eqn #1 for x:
{{{x=6000-y}}}
Substitute this value of x into Eqn #2:
{{{(6000-y)*0.09+y(0.11)=624}}}
Solve for y:
{{{540-0.09y+.11y=624}}}
{{{540+.02y=624}}}
{{{0.02y=84}}}
{{{highlight(y=4200)}}}
Now that you have the answer for y, plug that into Eqn #1 and solve for x:
{{{x+4200=6000}}}
{{{highlight(x=1800)}}}
You can check these answer by making sure each equation holds true when you plug in these values for x and y.
====================
Good Luck,
tutor_paul@yahoo.com