Question 1150882
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<pre>

Let x be the amount Linda invested at 6%.

Then the amount she invested at 12% is (12000-x).



The annual interest of the 6% investment is 0.06x.

The annual interest of the 6% investment is 0.12(12000-x).


The total interest is the sum of partial interests, which gives you this basic setup equation


    0.06x + 0.12*(12000-x) = 1200.


From the equation,


    x = {{{(1200-0.12*12000)/(0.06-0.12)}}} = 4000.


<U>ANSWER</U>.  The amount invested at 6% is 4000.


<U>CHECK</U>.   0.06*4000 + 0.12*(12000-4000) = 1200.    ! Precisely correct !
</pre>

Solved.


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It is a standard and typical problem on investments.


If you need more details,  &nbsp;or if you want to see other similar problems solved by different methods, &nbsp;look into the lesson 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/coordinate/lessons/Using-systems-of-equations-to-solve-problems-on-investment.lesson>Using systems of equations to solve problems on investment</A>

in this site.


You will find there different approaches &nbsp;(using one equation or a system of two equations in two unknowns), &nbsp;as well as 
different methods of solution to the equations &nbsp;(Substitution, &nbsp;Elimination).


Also, &nbsp;you have this free of charge online textbook in ALGEBRA-I in this site

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-I - YOUR ONLINE TEXTBOOK</A>.


The referred lesson is the part of this online textbook under the topic &nbsp;"<U>Systems of two linear equations in two unknowns</U>".



Save the link to this online textbook together with its description


Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson


to your archive and use it when it is needed.