Question 1189733
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<H3>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Instead of doing your homework for you, I'll do another one 
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;exactly like it with different numbers.</H3>


Robert invested $10000 in two different accounts, one at 6% annual interest and the other at 9%. 
How much did he invest in each account to get a yearly interest of $810? 
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<pre>
Let x = amount at 9%, in dollars.

Then the amount at 6% is the rest (10000-x) dollars.



The interest from the 9% amount is 0.09*x  dollars.

The interest from the 6%   amount is 0.06*(10000-x)   dollars.



Your equation is

    interest + interest      = total interest,   or


    0.09*x  + 0.06*(10000-x) = 810   dollars.


From the equation, express x and calculate the answer


    x = {{{(810 - 0.06*10000)/(0.09-0.06)}}} = 7000.


<U>Answer</U>.  The amount at 9% is $7000;  the rest  $10000-$7000 = $3000 is the amount at 6%.


<U>Check</U>.   0.06*3000 + 0.09*7000 = 810 dollars.   ! Correct !
</pre>

Solved.

<H3>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Now do yours the same way.</H3>

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It is a typical and standard problem on investment.


To see many other similar solved problems on investment, &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.