Question 353616
all these money type problems are set up the same way once u get used to seeing the pattern then you wont have trouble figuring out what needs to be done
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total=$12000
to get total add both portions x+y
so {{{x+y=12000}}}
4%=.04 and 5.5%=.055
the total interest amount is $532.50
so{{{.04x+.055y=532.5}}}
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So you have now found your 2 equations to bea ble to solve this problem, once you get used to doing these this process to finding the equations will come naturally.
{{{x+y=12000}}}
{{{.04x+.055y=532.5}}}
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You can solve by elimination or by substitution whichever you find more comfortable using, I like Elimination method as it is much faster.
{{{x+y=12000}}} multiply by .055
{{{.04x+.055y=532.5}}}
.
{{{.055x+.055y=660}}}
{{{.04x+.055y=532.5}}} subtract equations
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{{{.015x=127.5}}} divide by .015
{{{highlight(x=8500)}}} this is the portion at 4% interest
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Now instead of doing that whole process over to find "y" simply plug in the value of "x" in the equation {{{x+y=12000}}}
{{{(8500)+y=12000}}}
{{{highlight(y=3500)}}} this is the portion at 5.5% interest