Question 1092440
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It is a standard problem on investments.


If x is the amount at 4.5% and y is amount at 5.5%, then you have this system of two equations for two unknowns 


     x +      y = 9000,      (1)     (total amount)
0.045x + 0.055y = 447.       (2)     (owes)


To solve it, first multiply eq(2) by 10000. Then the system takes the form

     x +     y = 9000,       (1) 
   45x +   55y = 447000.     (2) 


Now  from eq(1) express   y = 9000 - x  and substitute into eq(2). You will get a single equation for x

45x + 55(9000-x) = 447000.


Simplify it step by step and solve for x:

45x + 495000 - 55x = 447000,

-10x = 447000 - 495000 = -48000  ====>  x = {{{(-48000)/(-10)}}} = 4800.


Thus the amount at 4.5% is just found. It is $4800.


Then the second amount is the rest of 9000:  y = 9000 - 4800 = 4200.


<U>Answer</U>.  $4800 at 4.5%  and  $4200 at 5.5%.
</pre>

Solved.



See 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.


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 "<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.