<PRE><B>Question 1133271</B>
.


Each day we solve &amp;nbsp;2-3-4 &amp;nbsp;similar problems at this forum.


Therefore, &amp;nbsp;I will give here only shortest version of the solution, &amp;nbsp;referring for more complete solutions/explanations to the lesson

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;- &lt;A HREF=https://www.algebra.com/algebra/homework/coordinate/lessons/Using-systems-of-equations-to-solve-problems-on-investment.lesson&gt;Using systems of equations to solve problems on investment&lt;/A&gt;

in this site.



&lt;U&gt;Solution&lt;/U&gt;


&lt;pre&gt;
Let x = the amount invested at 7% annual simple interest.

Then the amount invested at 4% is (32000-x) dollars.


Your basic equation is


    &lt;U&gt;interest&lt;/U&gt; + &lt;U&gt;interest&lt;/U&gt;       = &lt;U&gt;total interest&lt;/U&gt;,    or

    0.07x    + 0.04*(32000-x) = 1670


Simplify and solve for x:


    x = {{{(1670 -0.04*32000)/(0.07 - 0.04)}}} = 13000.


&lt;U&gt;ANSWER&lt;/U&gt;.  $13000 were invested at 7% and the rest,  $32000- $13000 = $19000 were invested at 4%.


&lt;U&gt;CHECK&lt;/U&gt;.    0.07*13000 + 0.04*19000 = 1670 dollars.    ! Correct !
&lt;/pre&gt;

Solved and completed.


------------------


It is a standard and typical problem on investments.


As I just said, &amp;nbsp;if you need more details,  &amp;nbsp;or if you want to see other similar problems solved by different methods, &amp;nbsp;look into the lesson 

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;- &lt;A HREF=https://www.algebra.com/algebra/homework/coordinate/lessons/Using-systems-of-equations-to-solve-problems-on-investment.lesson&gt;Using systems of equations to solve problems on investment&lt;/A&gt;

in this site.


You will find there different approaches &amp;nbsp;(using one equation or a system of two equations in two unknowns), &amp;nbsp;as well as 
different methods of solution to the equations &amp;nbsp;(Substitution, &amp;nbsp;Elimination).


Also, &amp;nbsp;you have this free of charge online textbook in ALGEBRA-I in this site

&amp;nbsp;&amp;nbsp;&amp;nbsp;&amp;nbsp;- &lt;A HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson&gt;ALGEBRA-I - YOUR ONLINE TEXTBOOK&lt;/A&gt;.


The referred lesson is the part of this online textbook under the topic &amp;nbsp;&quot;&lt;U&gt;Systems of two linear equations in two unknowns&lt;/U&gt;&quot;.



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.


</PRE>