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part of $5,200 is invested at an annual rate of 7 1/2% and remainder is invested at an annual rate 5%.
If the total number annual income from these two investments is $350, find the number of dollars
invested at the 5% rate.
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Let x be the amount (in dollars) invested at 5% rate.
Then the part invested at 7.5% is (5200-x) follars.
Then you have this total interest equation
0.05x + 0.075*(5200-x) = 350 dollars.
From the equation
x = = 1600.
ANSWER. The amount invested at 5% was 1600 dollars.
CHECK. The total interest 0.005*1600 + 0.075*(5200-1600) = 3500 dollars. ! Correct !
Solved.
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It is a standard and typical problem on investments.
If you need more details, or if you want to see other similar problems solved by different methods, look into the lesson
- Using systems of equations to solve problems on investment
in this site.
You will find there different approaches (using one equation or a system of two equations in two unknowns), as well as
different methods of solution to the equations (Substitution, Elimination).
Also, you have this free of charge online textbook in ALGEBRA-I in this site
- ALGEBRA-I - YOUR ONLINE TEXTBOOK.
The referred lesson is the part of this online textbook under the topic "Systems of two linear equations in two unknowns".
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.