<PRE><B>Question 923440</B>
x = liters of 30% solution
y = liters of pure acid
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30x + 100y = 45*15
x + y = 15
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put the system of linear equations into standard form
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30x + 100y = 675
x + y = 15
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copy and paste the above standard form linear equations in to this solver:
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answer:
x = 11.785714 liters of 30% solution
y = 3.2142857 liters of pure acid
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now solved by substitution:
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30x + 100y = 675
x + y = 15
x = 15 - y
30(15 - y) + 100y = 675
450 - 30y + 100y = 675
70y = 225
y = 225/70
y = 3.2142857 liters of pure acid
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