Algebra 1
posted by Julia .
Ms. Buxx invested a total of $2000 in two saving accounts. The first account pays 3% intrest per year. The second accout pays 5% intrest per year. If the intrest form both accounts totals $84 dollars per year how much is invested in each account?

Solve these two equations in two unknowns. Let X be the amount invested at 3% and Y be the amount invested at 5%.
X + Y = 2000
0.03 X + 0.05 Y = 84
I recommend substituting 2000X for Y in the second equaion, and than solving for X
The first step will give you
0.03 X + 0.05(2000X) = 0
0.03 X + 100  0.05X = 0
Take it from there. Solve for X and then use Y = 2000  X 
But then you get x=5000. Which is much more than the investment.

My mistake, sorry.
0.03 X + 100 0.05X = 84
16 = 0.02 X
X = 800
Y = 1200 
really and truly it would be simpler if you multiply everything in the second equation by 100 then solve with whole numbers