Liza deposits some money at 4.5 ​% ​interest, twice as much deposited at 5 ​%. amount deposited at each rate if the total annual interest income is ​$2175 .

Question

college algebra word problem

Answer 1

Hello, thank you for taking the time to post your question!

The key on this type of question is finding a way to relate the variables to one another in an algebraic expression. On this one we have

0.045x + 0.05(2x) = 2175  if you let “x” be the amount invested at the 4.5% rate

From there then you can solve for the value of “x” algebraically

0.045x + 0.10x = 2175

0.145x = 2175

x = 2175 / 0.145 = 15000

meaning that $15,000 was invested at the 4.5% rate and then (2*$15,000) = $30,000 was invested at the 5% rate

I hope that helps you get moving in a better direction on this type of question! Feel free to reach out if you have any additional questions beyond that :)

Answer 2

.045X + .05(2X) = 2175

.145X =2175

X = 2175/.145 = $15,000 invested at 4.5%

2X = $30,000 invested at 5%