<PRE><B>Question 1064823</B>
let x be the number of liters of the 70% solution
let y be the number of liters of the 50% solution
:
1) x + y = 10
:
2) 0.70x + 0.50y = 0.64 * 10 = 6.4
:
solve equation 1 for x
:
x = 10 - y
:
substitute for x in equation 2
:
0.70 * (10 - y) + 0.50y = 6.4
:
7 - 0.70y + 0.50y = 6.4
:
-0.20y = -0.60
:
y = 3
x = 7
:
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Dr. Alvarado mixes 7 liters of the 70% pure and
3 liters of the 50% pure
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:
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