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Expert: Sherry Wallin - 6/22/2010


Question
hi i meed help solving: y^2/3 + 9y^1/3 + 8=0

Answer
Kani~
  I am assuming you want(y^2)/3 + (9y)/3 + 8 = 0 by the way you have written the problem but somehow I think what you really want is y^(2/3) + 9y^(1/3) + 8 = 0 and in that case we are going to use 'u' substitution so let u = y^(1/3) so that u^2 = y^(2/3) and now you have u^2 + 9u + 8 = 0 which factors as (u + 1)(u + 8) = 0, so u + 1 = 0 and u + 8 = 0 which tells us that u = -1, -8. But do keep in mind you wanted y not u so now substitute y for
u: y^(1/3) = -1, cube both sides and you find that y = -1. y^(1/3) = -8, again cube both sides and you find that y = -512

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Sherry Wallin

Expertise

I can answer most questions up through Calculus and some in Number Theory and Abstract Algebra.

Experience

I have had my Bachelor's Degree since 1987 and have been a teacher since 1988. I earned my Masters Degree in Mathematics May 2010. I have been teaching at the same community college since 2002.

Education/Credentials
I have taught 12 years at the community college level, medical college, and technical college as well as a high school instructor and alternative education instructor and charter school instructor.

Awards and Honors
Master's GPA 3.56 Bachelor's GPA 3.34 Post grad work not degree related GPA 4.0

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