I have two story problems that have been plaguing me for days now. Solving them is not the issue; the issue is setting up the two equations. I have about 8 pages of attempts at setting them up, and nothing has come out right. These are both systems of linear equations with two variables in each. Here we go....
#1.
Money is invested at 10% and 13% simple interest, with annual interest from both investments, totaling $338.52. The amount invested at 13% exceeds twice the amount invested at 10% by $300. Find the amount invested at each rate.
For this I think I need 2(.13)+300 which is 300.26. When I add variables it looks like 338.52=.10x+2(.13y)+300 but I still need another equation in order to solve.
#2.
A collection of nickels and quarters is worth $2.15. If there are five more quarters than nickels, how many of each kind of coin are in the collection? (I was able, with some mental math, to figure out that there are 8 quarters and 3 nickels, but how do you set up the equations???)
#1.
Money is invested at 10% and 13% simple interest, with annual interest from both investments, totaling $338.52. The amount invested at 13% exceeds twice the amount invested at 10% by $300. Find the amount invested at each rate.
For this I think I need 2(.13)+300 which is 300.26. When I add variables it looks like 338.52=.10x+2(.13y)+300 but I still need another equation in order to solve.
#2.
A collection of nickels and quarters is worth $2.15. If there are five more quarters than nickels, how many of each kind of coin are in the collection? (I was able, with some mental math, to figure out that there are 8 quarters and 3 nickels, but how do you set up the equations???)
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