SOLUTION: Pharmer Phil needs to treat a field with potash and nitrogen. He knows he needs 308 pounds of potash and 330 pounds of nitrogen. He can use Grow Rite brand and Great Green brand. G

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: Pharmer Phil needs to treat a field with potash and nitrogen. He knows he needs 308 pounds of potash and 330 pounds of nitrogen. He can use Grow Rite brand and Great Green brand. G      Log On


   



Question 654227: Pharmer Phil needs to treat a field with potash and nitrogen. He knows he needs 308 pounds of potash and 330 pounds of nitrogen. He can use Grow Rite brand and Great Green brand. Grow Rite has 4 pounds of potash and 5 pounds of nitrogen per bag. Great Green has 7 pounds of potash and 6 pounds of nitrogen per bag. How many bags of each brand should Pharmer Phil use to treat his field?
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Let represent the number of bags of the GR brand and represent the number of bags of GG brand.

You get 4 lbs of potash per bag of GR, so the weight of potash attributable to GR brand is , likewise the weight of potash from the GG brand is . The sum of these must be 308 lbs, so:



Similarly, for the nitrogen,



Solve the 2X2 system by your choice of methods. I used the Elimination method and checked my work with Cramer's Rule in an Excel spreadsheet.

Let me know what you got.

John

My calculator said it, I believe it, that settles it
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