SOLUTION: willie cabaysa invests $10200 at 8 1/2%. how much money must he invest at 7% so that his total annual income from the two investments will equal 8% of the total principal?

Question 847923: willie cabaysa invests $10200 at 8 1/2%. how much money must he invest at 7% so that his total annual income from the two investments will equal 8% of the total principal?
Found 2 solutions by gksetu, richwmiller:
Answer by gksetu(9) (Show Source): You can put this solution on YOUR website!
$6800
Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!
0.085*10200+0.07(x)=0.08(10200+x)
Multiply out.
867.0+0.07(x)=816+0.08x
combine like terms
-0.01x=-51.0
isolate x
x=-51.0/-0.01
Divide
x=5100.0
check
0.085*10200+0.07(x)=0.08(10200+x)
867.0+0.07*5100.0=0.08(10200+5100.0)
867.0+357.0=0.08(15300.0)
1224.0=1224.0
ok

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