<PRE><B>Question 212813</B>
you have 2 equations that need to be solved simultaneously.
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x + y = 30,000
.075x + .06y = 2100
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multiply first equation by .06 to get:
.06x + .06y = 1800
subtract it from second equation of:
.075x + .06y = 2100 to get:
.015x = 300
divide both sides by .015 to get:
x = 20,000
this makes:
y = 10,000
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.075 * 20,000 + .06 * 10,000 = 1500 + 600 = 2100
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answer is:
she should invest $20,000 in the bond earning .075 interest rate per year and she should invest $10,000 in the bond earning .06 interest rate per year.
note:
.075 interest rate = 7.5%
.06 interest rate = 6%
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She will earn $2,100 in interest.
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