SOLUTION: In planning her retirement, Liza deposits some money at 4.5% interest, with twice as much deposited at 5%. Find the deposited at each rate if the total annual interest income is $1

Algebra ->  Linear-equations -> SOLUTION: In planning her retirement, Liza deposits some money at 4.5% interest, with twice as much deposited at 5%. Find the deposited at each rate if the total annual interest income is $1      Log On


   

Question 1093141: In planning her retirement, Liza deposits some money at 4.5% interest, with twice as much deposited at 5%. Find the deposited at each rate if the total annual interest income is $1450.
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
let x = the amount invested at 4.5%.
let y = the amount invested at 5.0%.

total interest is 1450.

therefore .045*x + .05*y = 1450.

y = 2 * x, so you can replace y with 2x and your equation becomes .045*x + .05*2*x = 1450

factor out the x to get x * (.045 + .05*2) = 1450

simplify and combine like terms to get .145 * x = 1450

solve for x to get x = 10000

2x is therefore equal to 20000.

she has 10000 invested at 4.5% and 20000 invested at 5%.

that's your solution.

.045 * 10000 + .05 * 20000 = 1450