SOLUTION: 2y^(2/3)+17y^(1/3)+30=0 I don't understand how to do this problem!

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Question 283306: 2y^(2/3)+17y^(1/3)+30=0

I don't understand how to do this problem!
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
2y^(2/3)+17y^(1/3)+30=0
let y^(1/3)=u
2u^2+17u+30=0
(u+6) (2 u+5) = 0
plug y^(1/3) back in for u
(y^(1/3)+6)*(2y^(1/3)+5)=0
(y^(1/3)+6)=0
y^(1/3)=-6
y=(-6)^3
(2y^(1/3)+5)=0
2y^(2/3)=-5
y^(2/3)=-5/2
y^2=(-5/2)^3
y^2 = -125/8
y=sqrt(-125/8)
y=-sqrt(-125/8)