# college alegebra

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solve the following equation in the real number system
3x^3 - 20x^2 + 29x +12 = 0
Ok I thought I knew how to do this but I guess I don't. Help me! Please!

• college alegebra -

A general cubic is hard to solve. So, expect an easy root first. Any rational root of the form a/b will be such that a divides 12 and b divides 3

A little synthetic division will show that

3x^3 - 20x^2 + 29x +12
= (x-3)(3x^2 - 11x - 4)
= (x-3)(x-4)(3x+1)

SO, knowing the factors, you should have no trouble finding the roots . . .

• college alegebra -

Thank you that helps a lot!

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