Question 1119192: Hi, I need some help with this interest problem, which I don't understand how to use a system of equations to solve it.
"Bruce invested in stock paying a 10.5% dividend. Maya invested $4,000 more than Bruce in a tax-free bonds paying 7˝% annual simple interest. If they invested for one year and Maya’s income from the investment was $75 more than Bruce’s, find out how much each invested."
Thank you!
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! Bruce invested in stock paying a 10.5% dividend. Maya invested $4,000 more than Bruce in a tax-free bonds paying 7˝% annual simple interest. If they invested for one year and Maya’s income from the investment was $75 more than Bruce’s, find out how much each invested."
:
let b = amt invested by Bruce
let m = amt invested by May
:
" Maya’s income from the investment was $75 more than Bruce’s,
.075m - .105b = 75
:
"Maya invested $4,000 more than Bruce", therefore
m = b + 4000
:
replace m with (b+4000) in the first equation
.075(b+4000) - .105b = 75
.075b + 300 -.105b = 75
.075b - .105b = 75 - 300
-.03b = -225
b = -225/.03
b = $7,500 invested by Bruce
Find m
m = 7500 + 4000
m = $11,500 invested by May
:
Check this by finding the actual amt each received
.075(11500) = $862.50
.105(7500) = $787.50
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income diff:= $75
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