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What are the real roots of 2x^3-42x-40

User Genxgeek
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1 Answer

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2x^3-42x-40=0
2x^3-42x=40
2x(x^2-21)=40
a. 2x=40=>x=20
b. x^2=21+40=>x^2=61=>x=+-(radical(61)
User Bryan Larsen
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