SOLUTION: 2 LINEAR EQUATIONS IN 2 UNKNOWNS or SIMULTANEOUS LINEAR EQUATIONS IN 2 UKNOWNS
the annual return on two investment totals P464. one investment gives 8% interest and the other 7.
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the annual return on two investment totals P464. one investment gives 8% interest and the other 7.
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Question 1122281: 2 LINEAR EQUATIONS IN 2 UNKNOWNS or SIMULTANEOUS LINEAR EQUATIONS IN 2 UKNOWNS
the annual return on two investment totals P464. one investment gives 8% interest and the other 7.5%. how much money is invested at each rate if the total investment is P6000 Answer by ikleyn(52788) (Show Source):
Let x = amount invested at 8%, in dollars.
Then the amount invested at 7.5% is the rest (6000-x) dollars.
The interest from the 8% amount is 0.08*x dollars.
The interest from the 7.5% amount is 0.075*(6000-x) dollars.
Your equation is
interest + interest = total interest, or
0.08*x + 0.075*(6000-x) = 464 dollars.
x = = 2800.
Answer. The amount invested at 8% is $2800; the rest $6000-$2800 = $3200 is the amount invested at 7.5%.
Check. 0.08*2800 + 0.075*3200 = 464. ! Correct !
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It is a typical and standard problem on investment.
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).
