SOLUTION: A writer received $39,000 as royalty for her book. She invested part of the money in bonds paying 5% interest annually. The rest she invested in a life insurance policy paying 10%

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Question 907556: A writer received $39,000 as royalty for her book. She invested part of the money in bonds paying 5% interest annually. The rest she invested in a life insurance policy paying 10% interest annually. If the total interest from the investments after 1 year is $3350, how much did she invest in bonds?
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
Total amount of money invested: $39000
x+y=39000,
Total yearly interest for the two accounts is: $3350
0.05*x+0.1*y=3350
x=39000-y
Substitute for x
0.05*(39000-y)+0.1*y=3350
Multiply out
1950-0.05y+0.1*y=3350
Combine like terms.
0.05*y=1400
Isolate y
y=$28000.00 at 10%
x=39000-y
Calculate x
x=$11000.00 at 5%
Check
0.05*11000+0.1*28000=3350
550+2800=3350
3350=3350
If this statement is TRUE and neither x nor y is negative then all is well