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Re: Systems of Linear Equations
Posted:
Jan 28, 2011 10:29 PM


On Fri, 28 Jan 2011, mathematicsstudent wrote:
> The manager of a bulk foods establishment sells a trail mix for $8 per > pound and premium cashews for $15 per pound. The manager wishes to make > a 105pound trail mixcashew mixture that will sell for $12 per pound. > How many pounds of each should be used? > > I figured out that the first equation should be: > X + Y = 105 > > How do I write the other equation? I tried this, but it didn't work: > 08x + .15Y = 12 > 08 looks like a mistake. Did you mean .08? No. More sense is 8x + 15y = 12.
8$/lb * x lb + 15$/lb * y lb = 12$/lb
The dimensions aren't correct. The left hand side is dollars and the right hand side is dollars per pound.
Where did the notion of 15%, ie .15 come from?
> If you can guide me along, I would greatly appreciate it!
8$/lb * x lb + 15$/lb * y lb = 12$/lb * how many lbs? = cost of the mix.



