SOLUTION: A baker purchased 17 lb of wheat flour and 14 lb of rye flour for a total cost of $21.30. A second purchase, at the same prices, included 18 lb of wheat flour and 12 lb of rye flou

Algebra ->  Equations -> SOLUTION: A baker purchased 17 lb of wheat flour and 14 lb of rye flour for a total cost of $21.30. A second purchase, at the same prices, included 18 lb of wheat flour and 12 lb of rye flou      Log On


   

Question 1054335: A baker purchased 17 lb of wheat flour and 14 lb of rye flour for a total cost of $21.30. A second purchase, at the same prices, included 18 lb of wheat flour and 12 lb of rye flour. The cost of the second purchase was $21.00. Find the cost per pound of the wheat flour and of the rye flour.
Answer by josgarithmetic(39614) About Me  (Show Source):
You can put this solution on YOUR website!
Wheat Flour price w
Rye Flour price r

system%2817w%2B14r=21.3%2C18w%2B12r=21%29

Help for a technique for solving, simplify the $21 accounting first.
18w%2B12r=21
3%2A6%2Aw%2B3%2A4%2Ar=3%2A7
6w%2B4r=7
Elimination could be a choice, but not too convenient unless YOU just find it so. I'd try substitution instead.

system%2817w%2B14r=21.3%2C6w%2B4r=7%29
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Changed my mind. TRY ELIMINATION. First equation by 2, second equation by 7.

system%2834w%2B28r=21.3%2A2%2C42w%2B28r=49%29

system%2834w%2B28r=42.6%2C42w%2B28r=49%29
and I stop here and you can complete the steps.