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put this solution on YOUR website!How many quarts of a pure solution must be added to a 5% solution to get 4 quarts of a 14.5% solution?
Convert the decimal to % solutions:
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We know that the amounts of the the two solutions add up 4 qt
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Let x = amt of pure solution
Pure solution is 1.00(x)
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Therefore the 5% solution amt is: .05[4-x]
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The resulting solution: .145(4)
The equation: .05[4-x] + 1.00[x] = .145(4)
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Mult, get rid of the brackets:
.2 - .05x + 1x = .58
1x - .05x = .58 - .2
.95x = .38
x = .38/.95
x = .4 qts of pure solution must be added
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Check by substitution: 5% amt = 4 - .4 = 3.6 qts
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.05(3.6) + .4 = .145[4)
.18 + .4 = .58 proves our value for x