SOLUTION: Find the solutions of 3x2/3 + 8x1/3 - 3 = 0.(eg.3 with u = x 1/3) College Algebra ISBN-13: 978-0-618-77629-0 Thanks

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Question 145561:
Find the solutions of 3x2/3 + 8x1/3 - 3 = 0.(eg.3 with u = x 1/3)
College Algebra ISBN-13: 978-0-618-77629-0
Thanks
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Find the solutions of 3x2/3 + 8x1/3 - 3 = 0
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You have a quadratic with variable x^(1/3).
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Let x^1/3 = w
Substitute to get:
3w^2 + 8w - 3 = 0
Use the AC Method or "Reverse Foil" to factor the left side:
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3w^2+9w-w-3 = 0
3w(w+3)-(w+3) = 0
(w+3)(3w-1) = 0
w = -3 or w = 1/3
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Substitute to get:
x^(1/3) = -3 or x^(1/3) = 1/3
x = (-3)^3 or x = (1/3)^3
x = -27 or x = 1/27
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Cheers,
Stan H.