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Bas_tet [7]
2 years ago
15

Brass is an alloy made by melting and mixing copper and zinc. A metallurgist has two brass

Mathematics
1 answer:
Drupady [299]2 years ago
4 0

Answer:

  • x +y = 500
  • 0.65x +0.95y = 0.75(500)
  • solution: (x, y) = (300, 200)

Step-by-step explanation:

A system of equations for the problem can be written using the two given relationships between quantities of brass alloys.

<h3>Setup</h3>

Let x and y represent the quantities in grams of the 65% and 90% alloys used, respectively. There are two relations given in the problem statement.

  x + y = 500 . . . . . . quantity of new alloy needed

  0.65x +0.90y = 0.75(500) . . . . . quantity of copper in the new alloy

These are the desired system of equations.

<h3>Solution</h3>

This problem does not ask for the solution, but it is easily found using substitution for x.

  x = 500 -y

  0.65(500 -y) +0.90y = 0.75(500)

  (0.90 -0.65)y = 500(0.75 -0.65) . . . . . . subtract 0.65(500)

  y = 500(0.10/0.25) = 200

  x = 500 -200 = 300

300 grams of 65% copper and 200 grams of 90% copper are needed.

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Math help questions <br>​
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After 1 year, the initial investment increases by 7%, i.e. multiplied by 1.07. So after 1 year the investment has a value of $800 × 1.07 = $856.

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