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olve the system of equations you developed in the last question algebraically (u

ID: 3410809 • Letter: O

Question

olve the system of equations you developed in the last question algebraically (using either substitution or elimination). To determine what amount of money/principle x must be invested to have the same amount in each account at the end of the two-year period. Then find the interest (plus bonus if applicable) that the accounts would have in addition to principle at the end of the 2 year period. Be sure to state which method you are using, show all work, then give the meaning of your solution in the context of the problem. Remember that a system of equations has an ordered pair as a solution so you should be telling me what each value means (x, y). y=0.06x y=0.04x+20

Explanation / Answer

1. We have y = 0.06x ; y = 0.04x + 20. This means that the interest on one account is 0.06x and that the interest on the other account is 0.04x + 20, after a 2 year period. Since the amount + bonus/interest in the two accounts is equal at the end of 2 year period, we have x + 0.06x = x + 0.04x + 20 or, x + 0.06x - x - 0.04x = 20 or, 0.02x = 20 so that x = 20/0.02 = 1000. The interest on the 1st account is 6/2 = 3 % p.a. while the interest on the 2nd account is 4/2 = 2 % p.a. However, there is a bonus of $ 20 per $ 1000 invested in the 2nd account. Here x is the prinxcipal amount or the initial amount invested, and y is the interest or the interest + bonus ( as the case may be) on x for 2 years.